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How to Save 20% Energy: An Example
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It's not that hard to reduce your energy use by 20%. In fact, it is very simple.
A home in suburban Washington DC has done that.
The example home uses electricity for cooling in summer but use gas for heating in
winter. They also use gas for cooking. So most of the saving will come from using less for cooling in summer.
Throughout the year savings from using less for lighting is also achieved.
The following measures are taken on a daily basis:
- Turn off outdoor lighting when not needded.
- Never leave outdoor lighting on overnight.
- Turn off lights when leaving a room.
- In summer, raise thermostats by 3-5 °F, or more when no one is home or during the night.
- In winter, lower thermostats by 3-5 °F, or more when no one is home or during the night.
Comparison: Before & After Energy-Saving Measures
| Month | Year Before (kWh) | Year After (kWh) | After/Before |
| 1 | 947 | 791 | 83.5% |
| 2 | 731 | 683 | 93.4% |
| 3 | 571 | 550 | 96.3% |
| 4 | 637 | 530 | 83.2% |
| 5 | 823 | 730 | 88.7% |
| 6 | 1682 | 954 | 56.7% |
| 7 | 1969 | 951 | 48.3% |
| 8 | 1785 | 851 | 47.7% |
| 9 | 620 | 610 | 98.4% |
| 10 | 773 | 611 | 79.0% |
| 11 | 904 | 686 | 75.9% |
| 12 | 945 | 884 | 93.5% |
| Total | 12387 | 8831 | 71.3% |
Notice that in this example a dramatic reduction in energy usage has been achieved
during the three summer months. More savings would have been achieved in winter if
electricity had been used for heating. Also during spring and fall savings are achieved by using less lighting.
The savings from lighting doesn't appear to be very large, that's because this home
had been very careful with the lighting before the energy-saving measures were taken. For example, they rarely lelt the porch lights on overnight.
The overall year-round saving is 28.7%.
You can do it, too. Start Now!
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The following forecast is received by this example home every day
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Weather, Power, and CO2 Emission Forecast
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Date
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Low
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High
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Precip
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Power Use
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CO2
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Dec 03
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25 °F
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50 °F
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4%
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27.1 kWh
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36.9 lb
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Dec 04
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31 °F
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50 °F
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39%
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26.1 kWh
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35.5 lb
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Dec 05
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26 °F
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41 °F
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18%
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28.5 kWh
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38.8 lb
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Dec 06
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22 °F
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37 °F
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24%
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29.9 kWh
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40.7 lb
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Dec 07
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24 °F
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40 °F
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28%
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28.8 kWh
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39.2 lb
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Dec 08
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20 °F
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42 °F
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15%
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29.2 kWh
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39.7 lb
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Dec 09
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25 °F
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43 °F
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36%
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28.2 kWh
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38.4 lb
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Temperature Forecast Chart
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Energy Use Forecast Chart
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CO2 Emission Forecast Chart
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Weather Sensitivity of Your Electricity Use
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Electricity Usage Formula for Summer:
E = 17.67 + (1.43)CDD
Electricity Usage Formula for Winter:
E = 17.67 + (0.34)HDD
E: Daily Electricity Consumption in kWh;
CDD: Daily Cooling Degree Day;
HDD: Daily Heating Degree Day;
In a summer day:
If the weather is hotter by 1 °F, your daily electricity consumption would go up by 1.43 kWh.
In a winter day:
If the weather is colder by 1 °F, your daily electricity consumption would go up by 0.34 kWh.
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Your Weather-Electricity-CO2 Look-Up Tablle
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This table makes it easy for you to find your daily electricity usage based on the mean temperature of the day.
In the table, first column, T, is the mean temperature of the day and can be calculated by taking average
of the high and low temperature of the day. the 2nd through the 5th columns are, respectively, daily electricity consumption, the CO2 emission, the HDD and CDD.
This table is derived by using the summer and winter formula shown above.
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T (°F)
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U (kWh)
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CO2 (lb)
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HDD
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CDD
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0
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39.77
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54.09
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65
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0
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1
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39.43
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53.62
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64
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0
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2
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39.09
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53.16
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63
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0
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3
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38.75
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52.7
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62
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0
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4
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38.41
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52.24
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61
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0
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5
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38.07
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51.78
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60
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0
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6
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37.73
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51.31
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59
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0
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7
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37.39
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50.85
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58
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0
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8
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37.05
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50.39
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57
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0
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9
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36.71
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49.93
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56
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0
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10
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36.37
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49.46
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55
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0
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11
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36.03
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49
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54
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0
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12
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35.69
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48.54
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53
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0
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13
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35.35
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48.08
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52
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0
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14
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35.01
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47.61
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51
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0
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15
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34.67
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47.15
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50
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0
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16
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34.33
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46.69
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49
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0
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17
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33.99
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46.23
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48
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0
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18
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33.65
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45.76
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47
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0
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19
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33.31
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45.3
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46
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0
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20
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32.97
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44.84
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45
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0
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21
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32.63
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44.38
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44
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0
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22
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32.29
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43.91
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43
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0
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23
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31.95
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43.45
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42
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0
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24
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31.61
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42.99
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41
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0
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25
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31.27
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42.53
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40
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0
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26
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30.93
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42.06
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39
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0
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27
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30.59
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41.6
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38
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0
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28
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30.25
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41.14
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37
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0
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29
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29.91
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40.68
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36
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0
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30
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29.57
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40.22
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35
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0
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31
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29.23
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39.75
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34
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0
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32
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28.89
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39.29
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33
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0
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33
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28.55
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38.83
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32
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0
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34
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28.21
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38.37
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31
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0
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35
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27.87
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37.9
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30
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0
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36
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27.53
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37.44
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29
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0
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37
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27.19
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36.98
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28
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0
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38
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26.85
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36.52
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27
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0
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39
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26.51
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36.05
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26
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0
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40
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26.17
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35.59
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25
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0
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41
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25.83
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35.13
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24
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0
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42
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25.49
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34.67
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23
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0
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43
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25.15
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34.2
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22
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0
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44
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24.81
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33.74
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21
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0
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45
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24.47
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33.28
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20
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0
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46
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24.13
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32.82
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19
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0
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47
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23.79
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32.35
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18
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0
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48
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23.45
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31.89
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17
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0
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49
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23.11
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31.43
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16
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0
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50
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22.77
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30.97
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15
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0
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51
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22.43
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30.5
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14
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0
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52
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22.09
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30.04
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13
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0
| |
53
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21.75
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29.58
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12
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0
| |
54
|
21.41
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29.12
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11
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0
| |
55
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21.07
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28.66
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10
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0
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56
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20.73
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28.19
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9
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0
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57
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20.39
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27.73
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8
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0
| |
58
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20.05
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27.27
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7
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0
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59
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19.71
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26.81
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6
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0
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60
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19.37
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26.34
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5
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0
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61
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19.03
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25.88
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4
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0
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62
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18.69
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25.42
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3
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0
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63
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18.35
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24.96
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2
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0
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64
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18.01
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24.49
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1
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0
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65
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17.67
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24.03
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0
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0
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66
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19.1
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25.98
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0
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1
| |
67
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20.53
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27.92
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0
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2
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68
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21.96
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29.87
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0
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3
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69
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23.39
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31.81
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0
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4
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70
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24.82
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33.76
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0
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5
| |
71
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26.25
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35.7
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0
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6
| |
72
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27.68
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37.64
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0
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7
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73
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29.11
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39.59
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0
|
8
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74
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30.54
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41.53
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0
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9
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75
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31.97
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43.48
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0
|
10
| |
76
|
33.4
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45.42
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0
|
11
| |
77
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34.83
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47.37
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0
|
12
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78
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36.26
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49.31
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0
|
13
| |
79
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37.69
|
51.26
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0
|
14
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80
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39.12
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53.2
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0
|
15
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81
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40.55
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55.15
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0
|
16
| |
82
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41.98
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57.09
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0
|
17
| |
83
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43.41
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59.04
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0
|
18
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84
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44.84
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60.98
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0
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19
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85
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46.27
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62.93
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0
|
20
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86
|
47.7
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64.87
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0
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21
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87
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49.13
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66.82
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0
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22
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88
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50.56
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68.76
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0
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23
| |
89
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51.99
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70.71
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0
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24
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90
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53.42
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72.65
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0
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25
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91
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54.85
|
74.6
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0
|
26
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92
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56.28
|
76.54
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0
|
27
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93
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57.71
|
78.49
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0
|
28
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94
|
59.14
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80.43
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0
|
29
| |
95
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60.57
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82.38
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0
|
30
| |
96
|
62
|
84.32
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0
|
31
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97
|
63.43
|
86.26
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0
|
32
| |
98
|
64.86
|
88.21
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0
|
33
| |
99
|
66.29
|
90.15
|
0
|
34
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100
|
67.72
|
92.1
|
0
|
35
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