| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2019 | 8.73 | 8.97 | 8.34 |
| 2018 | 13.75 | 16.89 | 8.41 |
| 2017 | 14.72 | 20.65 | 12.01 |
| 2016 | 19.51 | 26.83 | 15.17 |
| 2015 | 19.72 | 29.52 | 10.07 |
| 2014 | 8.93 | 11.48 | 6.98 |
| 2013 | 8.90 | 12.89 | 7.06 |
| 2012 | 9.18 | 11.19 | 7.87 |
| 2011 | 9.41 | 11.82 | 7.88 |
| 2010 | 12.86 | 19.51 | 10.19 |
| 2009 | 25.44 | 39.12 | 16.47 |
| 2008 | 24.61 | 32.26 | 15.06 |
| 2007 | 22.06 | 37.69 | 15.33 |
| 2006 | 13.18 | 16.92 | 10.89 |
| 2005 | 9.19 | 11.64 | 6.71 |
| 2004 | 15.59 | 20.41 | 10.64 |
| 2003 | 14.19 | 19.71 | 12.16 |
| 2002 | 20.73 | 25.85 | 15.01 |