| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.22 | 1.37 | 1.06 |
| 2023 | 1.12 | 1.37 | 0.86 |
| 2022 | 0.86 | 1.1 | 0.66 |
| 2021 | 0.68 | 0.78 | 0.6 |
| 2020 | 0.78 | 1.27 | 0.33 |
| 2019 | 9.84 | 33.65 | 0.37 |
| 2018 | 18.96 | 32.27 | 11.49 |
| 2017 | 22.27 | 24.78 | 18.2 |
| 2016 | 17.77 | 28.67 | 7.13 |
| 2015 | 10.99 | 19.39 | 5.57 |
| 2014 | 6.15 | 9.96 | 3.73 |
| 2013 | 5.65 | 7.79 | 3.85 |
| 2012 | 7.47 | 10.2 | 6.06 |
| 2011 | 9.15 | 11.03 | 6.66 |
| 2010 | 9.85 | 13.46 | 6.73 |
| 2009 | 8.91 | 11.87 | 5.83 |
| 2008 | 11.62 | 25.43 | 3.79 |
| 2007 | 18.16 | 30.73 | 9.82 |
| 2006 | 12.1 | 17.15 | 9.1 |
| 2005 | 9.94 | 13.06 | 5.75 |
| 2004 | 11.72 | 20.88 | 7.52 |