| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2020 | 12.31 | 14.43 | 10.84 |
| 2019 | 10 | 11.66 | 8.29 |
| 2018 | 15.1 | 23.52 | 8.6 |
| 2017 | 25.48 | 29.63 | 21.21 |
| 2016 | 23.38 | 28.9 | 17.97 |
| 2015 | 29.87 | 42.77 | 20.55 |
| 2014 | 24.14 | 29.83 | 19.71 |
| 2013 | 20.21 | 25.39 | 13.44 |
| 2012 | 22.21 | 30.65 | 15.75 |
| 2011 | 33.1 | 44.11 | 22.42 |
| 2010 | 27.18 | 34.07 | 18.76 |
| 2009 | 20.47 | 36.67 | 9.97 |
| 2008 | 19.49 | 52.19 | 6.66 |
| 2007 | 36.8 | 55.26 | 21.93 |
| 2006 | 21.52 | 30.37 | 15.58 |
| 2005 | 48.69 | 155.68 | 23.35 |
| 2004 | 34.44 | 50.73 | 26.51 |
| 2003 | 42.58 | 51.32 | 29.8 |
| 2002 | 32.68 | 41.79 | 29.03 |
| 2001 | 194.46 | 389.98 | 83.9 |
| 2000 | 81.84 | 103.19 | 62.67 |
| 1999 | 39.03 | 50.65 | 30.25 |
| 1998 | 33.04 | 42.84 | 26.59 |