| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 1.5 | 2.55 | 0.46 |
| 2023 | 1.98 | 2.76 | 1.57 |
| 2022 | 1.84 | 2.29 | 1.43 |
| 2021 | 1.64 | 2.12 | 1.14 |
| 2020 | 1.17 | 1.72 | 0.63 |
| 2019 | 1.12 | 1.55 | 0.78 |
| 2018 | 2.41 | 5.29 | 0.96 |
| 2017 | 6.72 | 8.9 | 4.37 |
| 2016 | 8.22 | 13.73 | 4.87 |
| 2015 | 11.61 | 17.97 | 6.81 |
| 2014 | 17.89 | 28.13 | 12.49 |
| 2013 | 16.28 | 27.51 | 7.01 |
| 2012 | 23.09 | 56.95 | 6.36 |
| 2011 | 72.48 | 95.41 | 44.98 |
| 2010 | 68.75 | 101.41 | 38.67 |
| 2009 | 22.86 | 52.05 | 6.96 |
| 2008 | 10.2 | 18.99 | 4.36 |
| 2007 | 25.64 | 55.37 | 13.01 |
| 2006 | 14.33 | 22.77 | 7.79 |
| 2005 | 8.65 | 12.12 | 6.13 |
| 2004 | 13.25 | 24.03 | 7.95 |