| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2020 | 8.25 | 8.91 | 7.44 |
| 2019 | 10.36 | 15.11 | 7.39 |
| 2018 | 8.63 | 10.13 | 6.92 |
| 2017 | 12.11 | 16.48 | 8.91 |
| 2016 | 10.61 | 15.56 | 7.27 |
| 2015 | 13.85 | 29.15 | 7.92 |
| 2014 | 10.16 | 14.19 | 8.33 |
| 2013 | 11.95 | 19.27 | 8.02 |
| 2012 | 18.6 | 21.16 | 16.14 |
| 2011 | 16.29 | 21.04 | 13.23 |
| 2010 | 18.48 | 28.25 | 13.58 |
| 2009 | 24.22 | 34.34 | 12.75 |
| 2008 | 16.66 | 27.32 | 10.74 |
| 2007 | 22.78 | 29.48 | 14.3 |
| 2006 | 11.55 | 16.2 | 9.58 |
| 2005 | 15.12 | 21.19 | 10.11 |
| 2004 | 19.82 | 21.44 | 17.63 |