| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2018 | 12.25 | 17.57 | 8.14 |
| 2017 | 11.03 | 14.63 | 7.28 |
| 2016 | 7.94 | 11.93 | 6.91 |
| 2015 | 10.58 | 15.61 | 7.56 |
| 2014 | 6.31 | 8.09 | 5.6 |
| 2013 | 7.66 | 9.49 | 6.42 |
| 2012 | 8.65 | 10.52 | 6.67 |
| 2011 | 11.03 | 13.13 | 8.68 |
| 2010 | 10.54 | 13.04 | 7.98 |
| 2009 | 13.39 | 18.68 | 7.66 |
| 2008 | 14.63 | 24.22 | 8.4 |
| 2007 | 20.08 | 32.53 | 7.61 |