| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.36 | 3.56 | 3.24 |
| 2024 | 3.53 | 3.82 | 3.16 |
| 2023 | 3.48 | 4.06 | 3.11 |
| 2022 | 3.57 | 4.31 | 3.07 |
| 2021 | 3.96 | 4.66 | 3.25 |
| 2020 | 3.07 | 3.72 | 2.55 |
| 2019 | 3.9 | 5.44 | 3.1 |
| 2018 | 3.94 | 5.27 | 2.95 |
| 2017 | 4.65 | 6.13 | 3.97 |
| 2016 | 4.04 | 4.79 | 3.54 |
| 2015 | 6.05 | 8.42 | 4.66 |
| 2014 | 4 | 5.66 | 3.45 |
| 2013 | 2.9 | 5.54 | 1.91 |
| 2012 | 2.65 | 3.34 | 2.03 |
| 2011 | 4.19 | 5.27 | 2.77 |
| 2010 | 5.7 | 7.7 | 4.24 |
| 2009 | 6.39 | 8.37 | 3.83 |
| 2008 | 7.15 | 13.45 | 3.71 |
| 2007 | 13.67 | 20.08 | 11.36 |