| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.86 | 3.36 | 2.36 |
| 2024 | 2.54 | 3.49 | 1.82 |
| 2023 | 4.56 | 6.87 | 3.4 |
| 2022 | 3.78 | 5.71 | 2.74 |
| 2021 | 4.1 | 5.17 | 2.96 |
| 2020 | 4.38 | 5.59 | 3.49 |
| 2019 | 4.33 | 5.51 | 3.2 |
| 2018 | 5.22 | 7.49 | 3.32 |
| 2017 | 4.99 | 6.22 | 4.31 |
| 2016 | 8.01 | 23.22 | 5.18 |
| 2015 | 18.85 | 34.72 | 11.03 |
| 2014 | 10.85 | 15.9 | 7.07 |
| 2013 | 6.88 | 11.69 | 4.47 |
| 2012 | 6.85 | 8.73 | 5.24 |
| 2011 | 11.33 | 15.51 | 7.81 |
| 2010 | 12.18 | 16.12 | 9.48 |
| 2009 | 10.87 | 12.76 | 9.09 |
| 2008 | 12.98 | 19.17 | 8.21 |