| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.88 | 2.39 | 1.57 |
| 2023 | 2.5 | 3.53 | 1.78 |
| 2022 | 2.24 | 3.3 | 1.77 |
| 2021 | 3.36 | 4.13 | 2.83 |
| 2020 | 5 | 9.15 | 3.43 |
| 2019 | 4.8 | 6.73 | 2.59 |
| 2018 | 3.63 | 5.28 | 2.04 |
| 2017 | 3.33 | 5.45 | 1.93 |
| 2016 | 2.1 | 2.71 | 1.82 |
| 2015 | 2.82 | 4.05 | 1.81 |
| 2014 | 2.08 | 2.71 | 1.81 |
| 2013 | 2.14 | 2.86 | 1.44 |
| 2012 | 1.88 | 2.68 | 1.17 |
| 2011 | 3.19 | 4.52 | 2.37 |
| 2010 | 4.02 | 5.85 | 2.63 |
| 2009 | 3.93 | 5.35 | 2.63 |
| 2008 | 4.15 | 6.69 | 1.68 |
| 2007 | 4.49 | 5.45 | 3.57 |
| 2006 | 2.85 | 4.09 | 2.3 |
| 2005 | 2.84 | 4.89 | 1.86 |
| 2004 | 3.8 | 4.77 | 2.94 |
| 2003 | 2.85 | 3.3 | 2.42 |
| 2002 | 4.29 | 8.15 | 2.27 |
| 2001 | 7.95 | 10.17 | 5.75 |
| 2000 | 8.61 | 11.17 | 6.55 |
| 1999 | 11 | 19.31 | 8.74 |
| 1998 | 11.16 | 13.86 | 7.88 |