| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2019 | 31.15 | 44.44 | 20.02 |
| 2018 | 33.31 | 42.87 | 20.05 |
| 2017 | 24.96 | 30.87 | 20.66 |
| 2016 | 31.35 | 35.65 | 25.74 |
| 2015 | 41.77 | 78.3 | 25.51 |
| 2014 | 18.27 | 25.91 | 14.33 |
| 2013 | 14.35 | 17.99 | 11.55 |
| 2012 | 16.54 | 23.33 | 10.96 |
| 2011 | 25.27 | 30.57 | 20.02 |
| 2010 | 27.57 | 35.94 | 20.59 |
| 2009 | 27.43 | 31.47 | 23.66 |
| 2008 | 34.46 | 55.03 | 20.22 |
| 2007 | 39.85 | 49.89 | 30.47 |
| 2006 | 27.46 | 34.53 | 21.74 |
| 2005 | 20.06 | 24.87 | 9.03 |
| 2004 | 19.87 | 24.37 | 12.11 |