| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2020 | 5.73 | 8.21 | 4.44 |
| 2019 | 6.79 | 8.72 | 5.51 |
| 2018 | 9.07 | 15.7 | 6.3 |
| 2017 | 12.45 | 13.78 | 10.82 |
| 2016 | 20.39 | 38.6 | 11.78 |
| 2015 | 44.36 | 51.12 | 36.68 |
| 2014 | 81.54 | 129.38 | 33.54 |
| 2013 | 29.39 | 33.83 | 22.73 |
| 2012 | 18.64 | 29.55 | 9.01 |
| 2011 | 13.59 | 17.54 | 9.25 |
| 2010 | 16.9 | 25.56 | 14.18 |
| 2009 | 23.06 | 31.85 | 12.03 |
| 2008 | 19.98 | 40.88 | 9.04 |
| 2007 | 37.66 | 59.92 | 21.72 |
| 2006 | 19.68 | 32.25 | 13.07 |
| 2005 | 14.57 | 23.21 | 10 |
| 2004 | 24.39 | 34.09 | 19.14 |
| 2003 | 30.73 | 37.87 | 22.05 |
| 2002 | 31.28 | 37.55 | 21.49 |
| 2001 | 55.03 | 79.7 | 34.94 |
| 2000 | 90.3 | 132.14 | 45.84 |
| 1999 | 46.85 | 75.64 | 33.75 |
| 1998 | 389.61 | 523.11 | 257.29 |
| 1997 | 0 | -15.88 |