| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.87 | 2.09 | 1.77 |
| 2024 | 1.79 | 2.46 | 1.48 |
| 2023 | 2.03 | 2.61 | 1.71 |
| 2022 | 3.04 | 4.33 | 2.3 |
| 2021 | 2.53 | 2.97 | 2.23 |
| 2020 | 2.84 | 4.16 | 2.35 |
| 2019 | 3.41 | 6.47 | 2.4 |
| 2018 | 3.56 | 5.18 | 2.39 |
| 2017 | 5.85 | 8.07 | 4.71 |
| 2016 | 6.42 | 7.71 | 5.61 |
| 2015 | 14.28 | 24.43 | 5.29 |
| 2014 | 12.11 | 16.44 | 9.38 |
| 2013 | 11.34 | 13.81 | 7.27 |
| 2012 | 8.74 | 11.52 | 6.36 |
| 2011 | 12.42 | 14.76 | 9.58 |
| 2010 | 12.39 | 19.7 | 7 |
| 2009 | 7.55 | 12.47 | 2.52 |
| 2008 | 3.07 | 5.32 | 1.53 |