| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 4.88 | 6.57 | 0.63 |
| 2021 | 6.22 | 9.54 | 4.93 |
| 2020 | 6.87 | 9.32 | 5.55 |
| 2019 | 7.28 | 11.45 | 5.95 |
| 2018 | 11.24 | 14.61 | 7.65 |
| 2017 | 15.03 | 27.18 | 10.37 |
| 2016 | 24.32 | 30.68 | 17.59 |
| 2015 | 15.74 | 37.06 | 8.78 |
| 2014 | 7.63 | 11.38 | 5.13 |
| 2013 | 5.94 | 7.87 | 4.63 |
| 2012 | 5.44 | 7.45 | 3.35 |
| 2011 | 6.47 | 9.14 | 3.48 |
| 2010 | 6.72 | 8.32 | 5.17 |
| 2009 | 7.25 | 9.42 | 5.55 |
| 2008 | 7.5 | 14.5 | 4.25 |
| 2007 | 9.63 | 18.58 | 3.41 |
| 2006 | 2.93 | 3.5 | 2.09 |
| 2005 | 2.63 | 4.59 | 1.45 |
| 2004 | 6.58 | 11.44 | 3.46 |
| 2003 | 12.91 | 15.07 | 10.52 |
| 2002 | 9.9 | 13.25 | 5.7 |
| 2001 | 9.34 | 11.17 | 6.05 |
| 2000 | 10.75 | 15.87 | 7.22 |
| 1999 | 27.3 | 44.26 | 17.56 |
| 1998 | 4.9 | 6.68 | 3.6 |
| 1997 | 3.53 | 5.36 | 1.91 |