| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.5 | 6.31 | 4.98 |
| 2024 | 4.21 | 7.43 | 2.84 |
| 2023 | 6.3 | 9.02 | 4.57 |
| 2022 | 8.22 | 11.61 | 6.6 |
| 2021 | 20.03 | 33.78 | 10.48 |
| 2020 | 13.49 | 28.82 | 6.23 |
| 2019 | 5.03 | 7.54 | 4 |
| 2018 | 6.18 | 7.27 | 5.47 |
| 2017 | 6.8 | 7.5 | 6.19 |
| 2016 | 6.11 | 7.51 | 4.64 |
| 2015 | 6.56 | 8.59 | 2.94 |
| 2014 | 2.72 | 4 | 1.93 |
| 2013 | 2.14 | 2.84 | 1.57 |
| 2012 | 2.82 | 3.81 | 1.97 |
| 2011 | 3.73 | 4.79 | 2.89 |