| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.01 | 6.02 | 4.07 |
| 2024 | 3.82 | 6.3 | 2.85 |
| 2023 | 4.54 | 5.9 | 3.64 |
| 2022 | 3.86 | 5.01 | 3.09 |
| 2021 | 3.03 | 3.45 | 2.46 |
| 2020 | 3.58 | 3.99 | 3.05 |
| 2019 | 4.77 | 5.89 | 3.51 |
| 2018 | 4.49 | 6.15 | 3.06 |
| 2017 | 7.19 | 13.24 | 4.76 |
| 2016 | 11.18 | 14.2 | 8.97 |
| 2015 | 8.08 | 15.08 | 4.06 |
| 2014 | 4.34 | 5.97 | 3.45 |
| 2013 | 4.28 | 6.28 | 3.19 |
| 2012 | 3.89 | 5.16 | 3.05 |
| 2011 | 5.72 | 7.4 | 3.57 |
| 2010 | 5.33 | 7.2 | 3.99 |
| 2009 | 4.49 | 5.23 | 3.57 |
| 2008 | 4.27 | 7.23 | 2.47 |
| 2007 | 6.36 | 10.68 | 2.55 |
| 2006 | 2.21 | 2.76 | 1.83 |
| 2005 | 1.44 | 2.18 | 0.8 |
| 2004 | 1.71 | 2.47 | 1.21 |
| 2003 | 2.3 | 3.17 | 1.57 |
| 2002 | 3.5 | 3.94 | 2.57 |
| 2001 | 4.3 | 4.97 | 3.29 |
| 2000 | 3.59 | 4.74 | 2.68 |
| 1999 | 2.65 | 5.09 | 1.58 |
| 1998 | 2.69 | 3.87 | 1.71 |
| 1997 | 1.99 | 2.54 | 1.49 |