| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.07 | 3.3 | 2.6 |
| 2024 | 3.87 | 5 | 3.01 |
| 2023 | 4.16 | 5.7 | 3.08 |
| 2022 | 4.98 | 6.74 | 3.4 |
| 2021 | 3.55 | 5.9 | 2.5 |
| 2020 | 3.85 | 5.79 | 2.94 |
| 2019 | 4.06 | 4.85 | 3.19 |
| 2018 | 3.31 | 6.37 | 1.83 |
| 2017 | 11.22 | 15.06 | 6.38 |
| 2016 | 7.11 | 13.54 | 4.52 |
| 2015 | 6.17 | 10.84 | 3.67 |
| 2014 | 4.46 | 6.54 | 3.51 |
| 2013 | 4.23 | 5.77 | 3.34 |
| 2012 | 2.97 | 3.98 | 2.15 |