| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2019 | 7.63 | 7.98 | 7.3 |
| 2018 | 9.28 | 13.25 | 6.97 |
| 2017 | 17.22 | 25.66 | 10.77 |
| 2016 | 23.56 | 29.97 | 17.49 |
| 2015 | 14.71 | 25.77 | 7.19 |
| 2014 | 9.47 | 11.4 | 7.28 |
| 2013 | 13.60 | 17.16 | 11.14 |
| 2012 | 10.13 | 14.95 | 7.05 |
| 2011 | 11.42 | 17.54 | 7.67 |
| 2010 | 16.51 | 27.48 | 9.82 |
| 2009 | 18.09 | 32.27 | 6.12 |
| 2008 | 8.13 | 15.27 | 4.4 |