| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.03 | 9.38 | 2.2 |
| 2024 | 2.27 | 3.82 | 1.02 |
| 2023 | 3.01 | 5.27 | 1.73 |
| 2022 | 1.85 | 2.79 | 1.16 |
| 2021 | 0.93 | 1.55 | 0.59 |
| 2020 | 1.09 | 1.5 | 0.89 |
| 2019 | 1.07 | 1.46 | 0.87 |
| 2018 | 1.39 | 2.22 | 0.77 |
| 2017 | 3.06 | 4.38 | 1.98 |
| 2016 | 2.91 | 4.01 | 2.11 |
| 2015 | 3.64 | 5.69 | 1.85 |
| 2014 | 2.67 | 4.15 | 1.92 |
| 2013 | 1.89 | 2.48 | 1.48 |
| 2012 | 2.04 | 2.63 | 1.52 |
| 2011 | 3.43 | 4.87 | 1.96 |
| 2010 | 3.55 | 4.43 | 2.81 |
| 2009 | 4.15 | 5.5 | 2.58 |
| 2008 | 6.87 | 17.24 | 1.65 |
| 2007 | 6.49 | 16.01 | 2.54 |
| 2006 | 1.96 | 2.97 | 1.37 |
| 2005 | 1.52 | 1.99 | 1.22 |
| 2004 | 2.34 | 2.94 | 1.89 |
| 2003 | 2.89 | 3.5 | 2.17 |
| 2002 | 3.95 | 4.46 | 2.87 |
| 2001 | 5.07 | 6.47 | 3.4 |
| 2000 | 4.57 | 5.41 | 3.74 |
| 1999 | 4.37 | 6.02 | 3.68 |
| 1998 | 8.25 | 11.82 | 5.31 |
| 1997 | 9.56 | 12.67 | 5.74 |