| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 1.86 | 2.18 | 1.48 |
| 2023 | 2 | 2.86 | 1.44 |
| 2022 | 3.78 | 5.54 | 2.33 |
| 2021 | 3.77 | 8.16 | 1.79 |
| 2020 | 1.68 | 2 | 1.34 |
| 2019 | 1.9 | 2.59 | 1.48 |
| 2018 | 2.09 | 2.85 | 1.44 |
| 2017 | 2.62 | 3.25 | 2.05 |
| 2016 | 1.98 | 2.45 | 1.59 |
| 2015 | 2.66 | 4.45 | 1.67 |
| 2014 | 1.24 | 2.27 | 0.8 |
| 2013 | 1.92 | 3.99 | 0.83 |
| 2012 | 1.6 | 2.01 | 1.31 |
| 2011 | 2.75 | 3.78 | 1.59 |
| 2010 | 2.89 | 3.95 | 1.95 |
| 2009 | 3.41 | 4.56 | 2.72 |
| 2008 | 8.73 | 11.64 | 2.64 |
| 2007 | 5.58 | 9.67 | 2.71 |
| 2006 | 1.97 | 2.74 | 1.63 |
| 2005 | 2.23 | 2.9 | 1.62 |
| 2004 | 3.05 | 3.99 | 2.37 |
| 2003 | 2.92 | 3.44 | 2.47 |
| 2002 | 3.32 | 3.79 | 2.82 |
| 2001 | 4.15 | 4.95 | 2.9 |
| 2000 | 4.22 | 5.02 | 3.03 |
| 1999 | 5.08 | 7.32 | 3.63 |
| 1998 | 4.51 | 5.78 | 3.91 |