| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 1.97 | 3.19 | 0.63 |
| 2022 | 3.38 | 4.88 | 2.72 |
| 2021 | 7.48 | 15.23 | 3.12 |
| 2020 | 5.9 | 8.97 | 3.29 |
| 2019 | 7.99 | 13.68 | 4.81 |
| 2018 | 8.67 | 15.79 | 5.19 |
| 2017 | 5.96 | 9.87 | 3.3 |
| 2016 | 3.01 | 5.32 | 1.16 |
| 2015 | 1.29 | 2.37 | 0.63 |
| 2014 | 0.5 | 0.73 | 0.39 |
| 2013 | 0.75 | 1.23 | 0.48 |
| 2012 | 1.14 | 1.45 | 0.82 |
| 2011 | 1.34 | 1.8 | 0.86 |
| 2010 | 2.81 | 10.75 | 1.31 |
| 2009 | 11.29 | 37.06 | 0.98 |
| 2008 | 0.98 | 1.12 | 0.84 |
| 2007 | 0.82 | 0.87 | 0.79 |
| 2006 | 0.61 | 0.89 | 0.41 |
| 2005 | 0.45 | 0.56 | 0.28 |
| 2004 | 0.75 | 1.51 | 0.48 |