| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.89 | 4.64 | 3.38 |
| 2024 | 2.87 | 5.13 | 2.05 |
| 2023 | 2.76 | 4.86 | 2.34 |
| 2022 | 2.51 | 3.23 | 2.22 |
| 2021 | 2.34 | 2.8 | 1.95 |
| 2020 | 3.19 | 5.21 | 2.43 |
| 2019 | 2.49 | 5.89 | 1.85 |
| 2018 | 2.88 | 4.12 | 1.83 |
| 2017 | 4.48 | 5.51 | 3.32 |
| 2016 | 5.03 | 6.48 | 3.69 |
| 2015 | 4.4 | 9.05 | 2.63 |
| 2014 | 2.2 | 2.98 | 1.77 |
| 2013 | 2.29 | 2.62 | 2.01 |
| 2012 | 2.35 | 2.92 | 1.97 |
| 2011 | 6.77 | 9.88 | 2.27 |
| 2010 | 7.61 | 9.41 | 5.92 |
| 2009 | 5.35 | 7.37 | 2.79 |
| 2008 | 5.15 | 10.75 | 2 |
| 2007 | 8.5 | 14.1 | 4.63 |
| 2006 | 4.62 | 7.35 | 2.84 |
| 2005 | 3.1 | 3.99 | 2.49 |
| 2004 | 4.41 | 5.73 | 3.08 |
| 2003 | 4.21 | 4.72 | 2.65 |
| 2002 | 4.59 | 5.38 | 3.22 |
| 2001 | 5.37 | 6.86 | 3.75 |
| 2000 | 5.97 | 7.72 | 4.57 |
| 1999 | 3.97 | 5.27 | 2.83 |
| 1998 | 2.9 | 3.42 | 2.13 |
| 1997 | 3.57 | 5.49 | 2.45 |