| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.9 | 6.11 | 3.91 |
| 2024 | 4.14 | 5.24 | 2.68 |
| 2023 | 4.04 | 5.02 | 3.19 |
| 2022 | 4.4 | 6.66 | 3.05 |
| 2021 | 4.98 | 6.86 | 3.93 |
| 2020 | 6.06 | 8.92 | 4.15 |
| 2019 | 5.13 | 7.54 | 3.47 |
| 2018 | 5.39 | 7.82 | 3.39 |
| 2017 | 8.48 | 10.54 | 7.01 |
| 2016 | 12.24 | 15.66 | 8.72 |
| 2015 | 10.96 | 18.89 | 6.36 |
| 2014 | 10.23 | 12.55 | 7.4 |
| 2013 | 12.31 | 18.7 | 9.07 |
| 2012 | 9.59 | 12.41 | 7.81 |
| 2011 | 12.36 | 18.9 | 9.18 |
| 2010 | 17.92 | 21.52 | 14.4 |
| 2009 | 12.84 | 17.01 | 9.27 |