| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2018 | 18.63 | 24.29 | 14.9 |
| 2017 | 18.13 | 20.86 | 16.41 |
| 2016 | 19.18 | 21.8 | 16.02 |
| 2015 | 14.52 | 21.04 | 8.14 |
| 2014 | 13.25 | 32.94 | 9.77 |
| 2013 | 25.87 | 33.07 | 20.67 |
| 2012 | 30.57 | 36.09 | 24.15 |
| 2011 | 10.13 | 12.16 | 8.4 |
| 2010 | 13.25 | 19.68 | 9.25 |
| 2009 | 20.04 | 28.18 | 13.61 |
| 2008 | 24.05 | 44.3 | 14.58 |
| 2007 | 16.84 | 31.18 | 6.61 |