| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.21 | 3.83 | 2.66 |
| 2024 | 2.39 | 4.17 | 1.53 |
| 2023 | 2.86 | 3.24 | 2.57 |
| 2022 | 2.61 | 3.93 | 1.97 |
| 2021 | 2.22 | 2.83 | 1.84 |
| 2020 | 2.54 | 2.99 | 2.11 |
| 2019 | 3.01 | 4.04 | 2.4 |
| 2018 | 3.18 | 4.61 | 2.12 |
| 2017 | 5.22 | 6.59 | 4.27 |
| 2016 | 4.5 | 5.46 | 3 |
| 2015 | 5.41 | 9.34 | 2.57 |
| 2014 | 7.37 | 13.87 | 4.38 |
| 2013 | 7.74 | 15.41 | 3.01 |
| 2012 | 4.24 | 6.25 | 2.44 |
| 2011 | 5.19 | 8.04 | 3.44 |
| 2010 | 7.11 | 9.46 | 5.46 |
| 2009 | 4.79 | 7.03 | 2.93 |
| 2008 | 3.41 | 5.87 | 1.65 |