| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2019 | 13.14 | 15.16 | 11.28 |
| 2018 | 12.99 | 16.72 | 10.43 |
| 2017 | 16.24 | 18.72 | 13.64 |
| 2016 | 15.03 | 19.33 | 13.98 |
| 2015 | 25.17 | 37.12 | 17.94 |
| 2014 | 21.24 | 28.14 | 18.49 |
| 2013 | 21.82 | 31.17 | 17.08 |
| 2012 | 16.41 | 19.15 | 13.38 |
| 2011 | 21.66 | 26.37 | 15.57 |
| 2010 | 22.33 | 30.79 | 15.26 |
| 2009 | 30.86 | 38.08 | 24.84 |
| 2008 | 35.14 | 80.38 | 19.27 |
| 2007 | 56.55 | 106.04 | 34.74 |
| 2006 | 30.74 | 41.54 | 23.17 |
| 2005 | 29.07 | 40.23 | 19.6 |
| 2004 | 25.65 | 32.23 | 19.51 |
| 2003 | 23.35 | 26.41 | 19.39 |
| 2002 | 31.28 | 35.19 | 26.23 |
| 2001 | 39.36 | 48.36 | 28.19 |
| 2000 | 50.22 | 59.86 | 37.42 |
| 1999 | 50.55 | 78.75 | 38.5 |
| 1998 | 39.96 | 51.08 | 31.94 |