| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.3 | 4.8 | 3.83 |
| 2024 | 3.87 | 4.78 | 3.2 |
| 2023 | 4.76 | 5.86 | 4.17 |
| 2022 | 4.7 | 5.58 | 4.03 |
| 2021 | 4.58 | 6.08 | 3.98 |
| 2020 | 5.77 | 8.5 | 4.17 |
| 2019 | 5.08 | 6.99 | 4.29 |
| 2018 | 5.64 | 7.25 | 4.24 |
| 2017 | 7.69 | 8.47 | 6.68 |
| 2016 | 8.55 | 10.94 | 7.55 |
| 2015 | 11.96 | 25.08 | 6.62 |
| 2014 | 5.2 | 7.56 | 3.23 |
| 2013 | 3.51 | 4.86 | 2.88 |
| 2012 | 4.09 | 5.63 | 2.87 |
| 2011 | 6.26 | 7.73 | 4.69 |
| 2010 | 9.82 | 13.65 | 7.16 |
| 2009 | 8.9 | 10.87 | 7.22 |
| 2008 | 14.37 | 31.89 | 6.13 |
| 2007 | 25.78 | 36.13 | 12.8 |
| 2006 | 11.03 | 16.82 | 8.84 |
| 2005 | 7.76 | 10.06 | 4.79 |
| 2004 | 8.29 | 12.5 | 5.64 |