| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.59 | 4.11 | 3.1 |
| 2024 | 2.73 | 3.58 | 1.9 |
| 2023 | 3.08 | 3.49 | 2.75 |
| 2022 | 2.93 | 3.41 | 2.02 |
| 2021 | 3.34 | 4.64 | 2.7 |
| 2020 | 3.14 | 4.36 | 2.37 |
| 2019 | 3.43 | 5.1 | 2.55 |
| 2018 | 5.28 | 8.58 | 2.97 |
| 2017 | 9.49 | 15.66 | 6.67 |
| 2016 | 7.71 | 11.3 | 6.49 |
| 2015 | 13.95 | 20.79 | 7.82 |
| 2014 | 13.81 | 19.57 | 10.43 |
| 2013 | 14.36 | 19.66 | 9.85 |
| 2012 | 14.16 | 17.98 | 10.87 |
| 2011 | 16.48 | 19.6 | 13.31 |