| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2020 | 20.5 | 21.96 | 20.08 |
| 2019 | 19.08 | 23.41 | 12.47 |
| 2018 | 22.23 | 34.59 | 12.06 |
| 2017 | 26.83 | 32.02 | 19.03 |
| 2016 | 21.3 | 28.01 | 16.26 |
| 2015 | 30.47 | 48.71 | 21.55 |
| 2014 | 23.74 | 32.69 | 19.27 |
| 2013 | 35.1 | 44.34 | 26.82 |
| 2012 | 40.47 | 51.62 | 29.8 |
| 2011 | 52.77 | 71.5 | 31.09 |
| 2010 | 63.34 | 84.82 | 50.66 |
| 2009 | 47.84 | 63.28 | 34.65 |