| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 0 | ||
| 2021 | 0.41 | 0.41 | 0.41 |
| 2020 | 0.44 | 0.45 | 0.41 |
| 2019 | 1.76 | 3.26 | 0.3 |
| 2018 | 4.48 | 8.9 | 2.27 |
| 2017 | 8.56 | 12.97 | 6.03 |
| 2016 | 8.88 | 11.46 | 5.82 |
| 2015 | 7.03 | 10.69 | 4.38 |
| 2014 | 5.83 | 7.79 | 4.49 |
| 2013 | 7.47 | 9.18 | 5.81 |
| 2012 | 5.58 | 6.59 | 4.31 |
| 2011 | 10 | 16.59 | 4.56 |
| 2010 | 11.48 | 16.26 | 8.97 |