| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2020 | 8.35 | 8.84 | 7.48 |
| 2019 | 8.88 | 10.69 | 7.81 |
| 2018 | 11.48 | 18.49 | 7.36 |
| 2017 | 23.23 | 30.85 | 16.66 |
| 2016 | 24.54 | 33.03 | 17.44 |
| 2015 | 20.35 | 40.35 | 10.63 |
| 2014 | 8.84 | 12.21 | 7.29 |
| 2013 | 8.17 | 9.35 | 7.15 |
| 2012 | 8.27 | 9.54 | 7.35 |
| 2011 | 10.9 | 15.59 | 7.98 |
| 2010 | 15.41 | 20 | 13.05 |
| 2009 | 12.53 | 15.68 | 10.73 |
| 2008 | 17.03 | 24.43 | 10.11 |
| 2007 | 19.05 | 24.73 | 13.08 |
| 2006 | 13.84 | 19.11 | 11.22 |
| 2005 | 18.54 | 23.95 | 13.26 |
| 2004 | 20.11 | 25.06 | 17.42 |