| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.4 | 2.84 | 1.64 |
| 2024 | 1.77 | 2.28 | 1.4 |
| 2023 | 2.16 | 2.43 | 1.77 |
| 2022 | 1.96 | 2.39 | 1.59 |
| 2021 | 2.4 | 2.81 | 1.96 |
| 2020 | 2.96 | 3.79 | 2.38 |
| 2019 | 3.7 | 5.49 | 2.79 |
| 2018 | 5.04 | 6.63 | 3.88 |
| 2017 | 4.86 | 6.22 | 3.69 |
| 2016 | 6.2 | 8.84 | 5.16 |
| 2015 | 9.05 | 18.1 | 5.91 |
| 2014 | 7.72 | 10.18 | 6.39 |
| 2013 | 7.79 | 9.85 | 6.11 |
| 2012 | 7.99 | 9.28 | 5.54 |
| 2011 | 10.33 | 13.29 | 8.61 |