| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2021 | 31.99 | 42.91 | 23.74 |
| 2020 | 31.56 | 43.98 | 23.66 |
| 2019 | 26.93 | 31.77 | 22.18 |
| 2018 | 26.77 | 34.71 | 21.03 |
| 2017 | 23.6 | 32.59 | 18.12 |
| 2016 | 20.18 | 23.21 | 18.07 |
| 2015 | 23.3 | 31.02 | 19.13 |
| 2014 | 21.57 | 28.34 | 16.36 |
| 2013 | 32.3 | 42.55 | 20.33 |
| 2012 | 18.45 | 22.55 | 14.31 |
| 2011 | 32.91 | 46.54 | 18.64 |
| 2010 | 41.46 | 54.66 | 33.49 |
| 2009 | 0 | -6.89 | |
| 2008 | 47.79 | 58.68 | 40.11 |
| 2007 | 44.98 | 53.24 | 35.28 |
| 2006 | 30.5 | 41.28 | 17.78 |
| 2005 | 20.01 | 23.17 | 14.47 |
| 2004 | 21.36 | 29.27 | 14.55 |
| 2003 | 26.02 | 32.02 | 15.06 |
| 2002 | 23.84 | 28.98 | 20.29 |
| 2001 | 33.39 | 41.55 | 25 |
| 2000 | 36.17 | 41.97 | 31.7 |
| 1999 | 45.09 | 73.91 | 32.56 |
| 1998 | 38.46 | 48.82 | 29.44 |
| 1997 | 51.09 | 72.71 | 35.43 |