| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.5 | 6.77 | 3.63 |
| 2024 | 4.11 | 5.23 | 3.48 |
| 2023 | 4.61 | 5.57 | 3.51 |
| 2022 | 3.74 | 5.03 | 2.94 |
| 2021 | 5.45 | 7.19 | 3.44 |
| 2020 | 4.66 | 7.75 | 2.67 |
| 2019 | 3.45 | 4.51 | 2.87 |
| 2018 | 5.86 | 8.02 | 3.36 |
| 2017 | 6.18 | 8.27 | 5.32 |
| 2016 | 6.18 | 7.11 | 5.39 |
| 2015 | 7.63 | 9.7 | 5.57 |
| 2014 | 6.39 | 7.99 | 5.31 |
| 2013 | 8.12 | 9.74 | 6.55 |
| 2012 | 5.27 | 7.1 | 4.09 |
| 2011 | 6.8 | 9.3 | 4.37 |
| 2010 | 9.86 | 13.65 | 8.15 |