| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 8 | 8.42 | 7.76 |
| 2024 | 6.2 | 13.6 | 4.42 |
| 2023 | 8.12 | 10.41 | 6.91 |
| 2022 | 6.8 | 10.84 | 5.1 |
| 2021 | 6.85 | 8.6 | 5.38 |
| 2020 | 9.45 | 12.31 | 7.47 |
| 2019 | 7.26 | 10.48 | 4.26 |
| 2018 | 5.53 | 7.42 | 4.01 |
| 2017 | 8.29 | 11.22 | 6.64 |
| 2016 | 14.05 | 21.63 | 10.01 |
| 2015 | 15.34 | 29.41 | 8.28 |
| 2014 | 7.93 | 10.48 | 6.24 |
| 2013 | 10.19 | 13.56 | 6.65 |
| 2012 | 9.2 | 12.5 | 6.25 |
| 2011 | 9.74 | 10.96 | 8.47 |