| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 6.71 | 7.38 | 6.13 |
| 2025 | 8.47 | 9.68 | 6.93 |
| 2024 | 8.24 | 12.15 | 6.63 |
| 2023 | 6.2 | 8 | 4.38 |
| 2022 | 4.08 | 5.91 | 2.96 |
| 2021 | 4.91 | 7.1 | 3.81 |
| 2020 | 7.05 | 12.58 | 4.51 |
| 2019 | 7.11 | 10.86 | 4.52 |
| 2018 | 7.82 | 9.76 | 5.41 |
| 2017 | 9.38 | 10.77 | 8.62 |
| 2016 | 6.84 | 10.25 | 4.69 |
| 2015 | 13.15 | 23.97 | 4.76 |
| 2014 | 8.59 | 23.62 | 6.16 |
| 2013 | 12.75 | 18.71 | 7.84 |
| 2012 | 11.51 | 16.45 | 6.84 |
| 2011 | 9.87 | 12.86 | 6.97 |
| 2010 | 12.94 | 18.29 | 9.83 |