| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.6 | 4.3 | 3.04 |
| 2024 | 2.41 | 3.71 | 1.86 |
| 2023 | 2.33 | 3.22 | 1.81 |
| 2022 | 2.96 | 4.05 | 1.93 |
| 2021 | 2.74 | 4.64 | 1.93 |
| 2020 | 3.08 | 4.45 | 2.2 |
| 2019 | 3.68 | 4.52 | 3.18 |
| 2018 | 5.01 | 6.68 | 3.34 |
| 2017 | 4.77 | 4.99 | 4.04 |
| 2016 | 4.79 | 6.28 | 4.14 |
| 2015 | 5.48 | 8.83 | 3.46 |
| 2014 | 3.75 | 5.07 | 2.93 |
| 2013 | 2.39 | 3.02 | 1.88 |
| 2012 | 2.86 | 3.48 | 2.1 |
| 2011 | 5.43 | 7.95 | 2.46 |
| 2010 | 5.32 | 8.03 | 3.45 |
| 2009 | 3.16 | 4.55 | 1.4 |
| 2008 | 8.36 | 47.45 | 1.12 |
| 2007 | 11.69 | 41.86 | 3.89 |
| 2006 | 3.04 | 5.65 | 2.05 |
| 2005 | 2.86 | 4.13 | 2.07 |
| 2004 | 4.19 | 5.62 | 3.36 |
| 2003 | 6.19 | 9.48 | 3.42 |
| 2002 | 10.21 | 11.35 | 7.66 |
| 2001 | 12.54 | 17.68 | 9.12 |
| 2000 | 10.26 | 13.86 | 6.04 |
| 1999 | 4.63 | 6.59 | 2.74 |
| 1998 | 3.13 | 4.07 | 2.14 |
| 1997 | 2.18 | 2.84 | 1.63 |