| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.73 | 2.96 | 2.49 |
| 2024 | 2.63 | 3.52 | 2.11 |
| 2023 | 3.96 | 4.91 | 3.33 |
| 2022 | 4.09 | 4.97 | 3.17 |
| 2021 | 4.25 | 6.05 | 3.07 |
| 2020 | 3.28 | 4.11 | 2.42 |
| 2019 | 4.34 | 5.29 | 3.38 |
| 2018 | 6.82 | 8.32 | 3.98 |
| 2017 | 5.91 | 7.2 | 4.97 |
| 2016 | 6.86 | 12.84 | 4.34 |
| 2015 | 12.06 | 14.98 | 10.75 |
| 2014 | 9 | 12.84 | 6.69 |
| 2013 | 8.26 | 10.01 | 7 |
| 2012 | 7.77 | 9.52 | 6.6 |
| 2011 | 9.51 | 13.3 | 7.98 |
| 2010 | 9.9 | 14.25 | 7.51 |
| 2009 | 7.2 | 9.01 | 6.19 |
| 2008 | 9.07 | 15.02 | 4.04 |
| 2007 | 10.3 | 16.55 | 3.45 |
| 2006 | 3.84 | 4.85 | 2.75 |
| 2005 | 3.06 | 3.5 | 2.66 |
| 2004 | 5.03 | 7.17 | 2.79 |
| 2003 | 6.88 | 8.3 | 5.4 |
| 2002 | 10.37 | 12.31 | 8.65 |
| 2001 | 8.97 | 10.48 | 7.38 |