| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2021 | 16.9 | 19.87 | 14.75 |
| 2020 | 18.3 | 23.69 | 13.25 |
| 2019 | 18.08 | 21.98 | 13.33 |
| 2018 | 24.44 | 40.01 | 12.97 |
| 2017 | 31.33 | 39.08 | 22.7 |
| 2016 | 27.58 | 34.42 | 22.7 |
| 2015 | 36.88 | 52.96 | 22.41 |
| 2014 | 28.77 | 52.58 | 20.08 |
| 2013 | 55.29 | 66.37 | 42.44 |
| 2012 | 41.54 | 51.25 | 34.27 |
| 2011 | 44.49 | 60.26 | 33.23 |
| 2010 | 55.57 | 75.81 | 35.46 |
| 2009 | 32.5 | 54.53 | 25.01 |