| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2021 | 33.1 | 40.44 | 27.48 |
| 2020 | 23 | 36.19 | 16.63 |
| 2019 | 23.88 | 30.12 | 18.4 |
| 2018 | 25 | 32.01 | 18 |
| 2017 | 23.94 | 28.09 | 19.6 |
| 2016 | 21.84 | 25.55 | 17.99 |
| 2015 | 24.38 | 39.54 | 18.45 |
| 2014 | 16.96 | 19.69 | 14.81 |
| 2013 | 17.43 | 20.26 | 13.68 |
| 2012 | 17.23 | 21.19 | 14.57 |
| 2011 | 24.88 | 32.5 | 18.12 |