| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 7.24 | 8.33 | 6.21 |
| 2025 | 6.8 | 9.43 | 4.9 |
| 2024 | 5.61 | 7.37 | 4.14 |
| 2023 | 6.96 | 10.66 | 4.37 |
| 2022 | 4.31 | 5.52 | 3.49 |
| 2021 | 6.04 | 7.92 | 4.86 |
| 2020 | 8.57 | 11.49 | 7 |
| 2019 | 8.37 | 10.55 | 6.97 |
| 2018 | 9.42 | 12 | 6.96 |
| 2017 | 9.07 | 12.3 | 7.31 |
| 2016 | 16.71 | 29.74 | 11.55 |
| 2015 | 21.3 | 33.04 | 11.53 |
| 2014 | 12.67 | 19.49 | 8.78 |
| 2013 | 9.34 | 12.08 | 7.05 |
| 2012 | 8.98 | 12.27 | 6.95 |