| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.2 | 6.02 | 4.38 |
| 2024 | 3.23 | 4.36 | 2.41 |
| 2023 | 4.04 | 4.57 | 3.62 |
| 2022 | 3.91 | 5.26 | 2.78 |
| 2021 | 3.23 | 5.96 | 2.65 |
| 2020 | 3.32 | 3.95 | 2.65 |
| 2019 | 2.67 | 4.37 | 1.18 |
| 2018 | 2.31 | 4.68 | 1.13 |
| 2017 | 4.77 | 6.39 | 4.19 |
| 2016 | 5.09 | 6.39 | 3.33 |
| 2015 | 4.08 | 7.72 | 2.68 |
| 2014 | 2.67 | 3.37 | 2.15 |
| 2013 | 2.66 | 3.13 | 2.34 |
| 2012 | 2.88 | 3.71 | 2.27 |
| 2011 | 5.15 | 6.98 | 3.16 |
| 2010 | 7.8 | 9.88 | 6.48 |
| 2009 | 5.9 | 8.87 | 2.96 |
| 2008 | 5.77 | 12.81 | 1.9 |
| 2007 | 11.13 | 16.49 | 6.41 |
| 2006 | 4.14 | 6.69 | 1.79 |
| 2005 | 2.42 | 3.34 | 1.67 |
| 2004 | 5.09 | 9.17 | 3.17 |
| 2003 | 6.57 | 16.62 | 5.2 |
| 2002 | 11.46 | 16.79 | 1.67 |
| 2001 | 3.77 | 4.83 | 2.8 |
| 2000 | 4.16 | 5.19 | 3.46 |
| 1999 | 2.93 | 3.48 | 2.42 |
| 1998 | 3.39 | 4.41 | 2.43 |
| 1997 | 4.34 | 5.67 | 3.16 |