| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.99 | 4.08 | 3.88 |
| 2024 | 3.59 | 4.32 | 2.75 |
| 2023 | 3.06 | 3.55 | 2.58 |
| 2022 | 2.35 | 3.29 | 1.87 |
| 2021 | 2.49 | 3.24 | 2 |
| 2020 | 2.4 | 3.22 | 1.54 |
| 2019 | 2.3 | 2.97 | 1.73 |
| 2018 | 3.46 | 4.94 | 2.45 |
| 2017 | 4.8 | 5.33 | 4.34 |
| 2016 | 4.69 | 5.55 | 3.81 |
| 2015 | 4.91 | 6.27 | 3.72 |
| 2014 | 4.4 | 5.65 | 3.67 |
| 2013 | 6.43 | 9.03 | 5.26 |
| 2012 | 7.15 | 9.09 | 5.84 |
| 2011 | 10.22 | 14.49 | 8.03 |
| 2010 | 9.99 | 13.78 | 7.13 |
| 2009 | 7.18 | 9.77 | 5.62 |
| 2008 | 9.43 | 15.78 | 5.21 |
| 2007 | 10 | 16.07 | 4.91 |
| 2006 | 3.83 | 5.45 | 2.06 |
| 2005 | 2.89 | 3.95 | 1.98 |
| 2004 | 3.22 | 3.78 | 2.79 |
| 2003 | 3.05 | 3.43 | 2.6 |
| 2002 | 4.15 | 4.64 | 3.67 |
| 2001 | 4.44 | 4.97 | 3.72 |
| 2000 | 5.75 | 8.28 | 4.33 |
| 1999 | 4.99 | 6.01 | 3.89 |
| 1998 | 7.07 | 10.49 | 4.71 |
| 1997 | 5.95 | 8.44 | 4.25 |