| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 6.5 | 8.83 | 0.68 |
| 2022 | 7.98 | 12.15 | 5.35 |
| 2021 | 7.92 | 12.9 | 4.08 |
| 2020 | 5.46 | 6.68 | 4.15 |
| 2019 | 6.85 | 9.71 | 5.11 |
| 2018 | 7.13 | 10.22 | 5 |
| 2017 | 14.14 | 22.69 | 9.54 |
| 2016 | 18.37 | 26.27 | 10.54 |
| 2015 | 17.69 | 34.85 | 10.77 |
| 2014 | 8.73 | 11.79 | 4.54 |
| 2013 | 4.91 | 6.15 | 3.79 |
| 2012 | 4.16 | 5.51 | 3.33 |
| 2011 | 5.42 | 7.62 | 3.79 |
| 2010 | 5.17 | 6.82 | 3.92 |
| 2009 | 4.85 | 6.44 | 2.79 |
| 2008 | 4.36 | 7.36 | 1.98 |
| 2007 | 6.42 | 9.97 | 3.46 |
| 2006 | 3.37 | 4.72 | 2.31 |
| 2005 | 1.93 | 2.7 | 1.17 |
| 2004 | 3.03 | 3.98 | 2.47 |
| 2003 | 3.22 | 4.32 | 2.45 |
| 2002 | 5.35 | 5.89 | 4.12 |
| 2001 | 5.59 | 6.59 | 4.07 |
| 2000 | 5.98 | 9.11 | 2.98 |
| 1999 | 2.67 | 3.68 | 1.88 |
| 1998 | 3.31 | 4.14 | 2.44 |
| 1997 | 4.13 | 5.96 | 3.38 |