| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2020 | 20.91 | 23.96 | 18.72 |
| 2019 | 23.06 | 26.37 | 20.27 |
| 2018 | 35.95 | 73.57 | 18.77 |
| 2017 | 38.75 | 71.67 | 17.86 |
| 2016 | 18.81 | 25.9 | 16.63 |
| 2015 | 25.21 | 41.38 | 16.49 |
| 2014 | 13.84 | 20.97 | 12.07 |
| 2013 | 19.24 | 29.68 | 13.4 |
| 2012 | 32.77 | 50.83 | 24.23 |
| 2011 | 22.72 | 29.03 | 18.3 |
| 2010 | 18.94 | 24.94 | 12.89 |
| 2009 | 35.36 | 53.15 | 20.97 |
| 2008 | 20.87 | 33.59 | 13.42 |
| 2007 | 26.27 | 37.95 | 18.52 |
| 2006 | 14.34 | 18.72 | 12.81 |
| 2005 | 13.68 | 15.71 | 11.2 |
| 2004 | 15.45 | 20.41 | 12.29 |
| 2003 | 16.31 | 19.38 | 12.69 |
| 2002 | 18.68 | 21.26 | 16.92 |
| 2001 | 22.12 | 28.6 | 18 |
| 2000 | 31.53 | 40.72 | 20.75 |
| 1999 | 23.08 | 32.29 | 16.36 |
| 1998 | 26.4 | 38.41 | 18.9 |