| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.78 | 4.87 | 2.34 |
| 2024 | 2.39 | 3.5 | 1.32 |
| 2023 | 2.34 | 2.93 | 1.86 |
| 2022 | 2.91 | 3.82 | 2.32 |
| 2021 | 2.6 | 3.56 | 1.94 |
| 2020 | 3.38 | 4.28 | 2.53 |
| 2019 | 2.84 | 3.99 | 1.77 |
| 2018 | 2.11 | 2.87 | 1.45 |
| 2017 | 3.59 | 4.66 | 2.77 |
| 2016 | 3.94 | 4.89 | 3.22 |
| 2015 | 5.07 | 8.41 | 3.07 |
| 2014 | 5.13 | 6.22 | 4.46 |
| 2013 | 5.11 | 6.05 | 4.23 |
| 2012 | 5.93 | 8.01 | 4.39 |
| 2011 | 7.79 | 10.74 | 5.66 |
| 2010 | 8.43 | 11.28 | 6.47 |
| 2009 | 6.98 | 10.54 | 3.51 |
| 2008 | 5.74 | 10.79 | 2.77 |
| 2007 | 9.75 | 17.02 | 4.8 |
| 2006 | 3.73 | 5.03 | 2.69 |
| 2005 | 3.39 | 4.18 | 2.6 |
| 2004 | 6.15 | 11.38 | 3.73 |