| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.91 | 3.57 | 2.53 |
| 2024 | 2.3 | 3.88 | 1.73 |
| 2023 | 2.34 | 3.22 | 2.05 |
| 2022 | 2.39 | 3.19 | 1.99 |
| 2021 | 2.55 | 3.23 | 2.13 |
| 2020 | 2.93 | 3.84 | 2.35 |
| 2019 | 3.35 | 4.36 | 2.63 |
| 2018 | 3.98 | 6.02 | 2.58 |
| 2017 | 7.83 | 11.26 | 5.14 |
| 2016 | 8.59 | 10.69 | 6.52 |
| 2015 | 9.22 | 15.54 | 6.16 |
| 2014 | 6.33 | 8.32 | 5.05 |
| 2013 | 5.65 | 7.34 | 4.5 |
| 2012 | 4.41 | 5.2 | 3.7 |
| 2011 | 5.63 | 7.17 | 3.92 |
| 2010 | 6.73 | 9.17 | 4.82 |
| 2009 | 5.61 | 6.77 | 3.37 |
| 2008 | 4.68 | 7.86 | 2.78 |
| 2007 | 4.59 | 6.45 | 2.19 |
| 2006 | 2.08 | 2.67 | 1.48 |
| 2005 | 2.04 | 2.77 | 1.38 |
| 2004 | 3.04 | 4.16 | 2.26 |
| 2003 | 4.83 | 6.06 | 3.2 |
| 2002 | 5.37 | 6.45 | 3.74 |
| 2001 | 6.29 | 8.27 | 4.9 |
| 2000 | 5.92 | 7.16 | 5.1 |
| 1999 | 5.43 | 7.13 | 4.37 |
| 1998 | 4.29 | 5.29 | 3.5 |
| 1997 | 5.71 | 8.26 | 4.05 |