| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.75 | 0.92 | 0.69 |
| 2024 | 0.68 | 0.87 | 0.47 |
| 2023 | 0.72 | 0.81 | 0.63 |
| 2022 | 0.95 | 1.47 | 0.69 |
| 2021 | 1.37 | 2.02 | 1.07 |
| 2020 | 2.2 | 2.89 | 1.41 |
| 2019 | 2.93 | 4.49 | 2.13 |
| 2018 | 4.49 | 6.25 | 2.73 |
| 2017 | 6.91 | 8.92 | 4.72 |
| 2016 | 6.1 | 8.62 | 4.1 |
| 2015 | 5.56 | 10.82 | 3.43 |
| 2014 | 3.55 | 4.7 | 2.84 |
| 2013 | 2.23 | 2.84 | 1.62 |
| 2012 | 2.23 | 2.81 | 1.69 |
| 2011 | 3.02 | 4.02 | 1.99 |
| 2010 | 6.29 | 6.87 | 5.55 |
| 2009 | 3.31 | 7.12 | 1.39 |
| 2008 | 2.49 | 5.13 | 1.09 |
| 2007 | 3.97 | 6.05 | 2.7 |
| 2006 | 2.5 | 3.6 | 1.82 |
| 2005 | 1.78 | 2.27 | 1.34 |
| 2004 | 3.2 | 5.95 | 1.64 |