| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.1 | 6.09 | 4.09 |
| 2024 | 3.21 | 5.02 | 2.2 |
| 2023 | 3.72 | 4.66 | 3.01 |
| 2022 | 24.77 | 28.83 | 20.9 |
| 2021 | 12.22 | 28.11 | 4.25 |
| 2020 | 4.26 | 7.11 | 2.3 |
| 2019 | 2.55 | 3.26 | 1.95 |
| 2018 | 2.05 | 2.47 | 1.58 |
| 2017 | 2.44 | 3 | 2.12 |
| 2016 | 2.9 | 3.57 | 2.45 |
| 2015 | 4.6 | 8.67 | 2.3 |
| 2014 | 1.87 | 2.71 | 1.29 |
| 2013 | 1.34 | 1.66 | 1.15 |
| 2012 | 1.33 | 1.6 | 1.11 |
| 2011 | 1.94 | 2.43 | 1.39 |
| 2010 | 3.13 | 3.83 | 2.24 |
| 2009 | 2.59 | 3.32 | 1.71 |
| 2008 | 3.33 | 6.33 | 1.46 |
| 2007 | 4.92 | 7.41 | 2.01 |
| 2006 | 1.91 | 2.38 | 1.69 |
| 2005 | 2.32 | 3.48 | 1.7 |
| 2004 | 4.3 | 8.49 | 1.51 |
| 2003 | 5.48 | 6.84 | 2.85 |
| 2002 | 7.53 | 10.26 | 5.69 |
| 2001 | 11.78 | 15.75 | 9.26 |
| 2000 | 11.68 | 15.01 | 8.93 |
| 1999 | 6.99 | 12.15 | 4.65 |
| 1998 | 7.26 | 11.22 | 3.09 |
| 1997 | 4.49 | 6.92 | 3.38 |