| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.69 | 3.02 | 2.36 |
| 2024 | 2.72 | 3.31 | 2.1 |
| 2023 | 2.93 | 3.71 | 2.38 |
| 2022 | 3.61 | 4.97 | 2.75 |
| 2021 | 3.83 | 5.1 | 2.84 |
| 2020 | 3.66 | 5.52 | 2.58 |
| 2019 | 3.04 | 3.74 | 2.52 |
| 2018 | 3.8 | 5.42 | 2.25 |
| 2017 | 6.72 | 9.2 | 4.88 |
| 2016 | 9.25 | 12.77 | 7.83 |
| 2015 | 12.76 | 15.37 | 8.36 |
| 2014 | 6.94 | 10.28 | 5.28 |
| 2013 | 5.57 | 7.01 | 4.62 |
| 2012 | 7.41 | 9.66 | 4.78 |
| 2011 | 8.15 | 9.92 | 6.53 |