| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.99 | 4.62 | 2.31 |
| 2024 | 2.6 | 3.11 | 2.13 |
| 2023 | 3.89 | 4.97 | 2.95 |
| 2022 | 4.03 | 5.32 | 2.45 |
| 2021 | 5.21 | 6.86 | 3.87 |
| 2020 | 3.74 | 5.57 | 2.37 |
| 2019 | 2.7 | 4.06 | 1.97 |
| 2018 | 3.36 | 5.95 | 1.89 |
| 2017 | 7.35 | 11.73 | 4.84 |
| 2016 | 6.45 | 8.31 | 4.99 |
| 2015 | 6.11 | 9.8 | 4.04 |
| 2014 | 5.28 | 6.89 | 4.35 |
| 2013 | 4.38 | 5.52 | 3.56 |
| 2012 | 3.07 | 4.54 | 2.28 |
| 2011 | 6.5 | 10.7 | 2.84 |
| 2010 | 9.18 | 11.97 | 7.24 |
| 2009 | 4.84 | 7.88 | 3.44 |
| 2008 | 3.94 | 6.51 | 2.22 |