| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.13 | 5.92 | 4.71 |
| 2024 | 4.09 | 5.2 | 3 |
| 2023 | 3.66 | 4.24 | 3.06 |
| 2022 | 3.08 | 3.71 | 2.35 |
| 2021 | 4.19 | 5.66 | 3.26 |
| 2020 | 3.88 | 4.86 | 3 |
| 2019 | 4.03 | 5.04 | 3.42 |
| 2018 | 4.1 | 5.26 | 3.03 |
| 2017 | 6.39 | 8.37 | 4.88 |
| 2016 | 6.81 | 7.83 | 6.23 |
| 2015 | 8.78 | 13.41 | 5.98 |
| 2014 | 7.28 | 8.86 | 6.01 |
| 2013 | 7.18 | 8.73 | 6.18 |
| 2012 | 5.61 | 6.62 | 4.74 |