| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.94 | 2.12 | 1.72 |
| 2024 | 2.07 | 2.56 | 1.63 |
| 2023 | 3.82 | 8.37 | 1.58 |
| 2022 | 2.42 | 3.08 | 1.74 |
| 2021 | 1.65 | 3.68 | 1.13 |
| 2020 | 1.45 | 2.84 | 0.98 |
| 2019 | 1.15 | 1.42 | 0.94 |
| 2018 | 1.2 | 1.54 | 0.9 |
| 2017 | 2 | 2.69 | 1.49 |
| 2016 | 2.79 | 4.07 | 2.44 |
| 2015 | 3.69 | 7.31 | 2.16 |
| 2014 | 2.18 | 2.54 | 1.78 |
| 2013 | 4.45 | 9.37 | 2.37 |
| 2012 | 6.15 | 7.79 | 4.5 |
| 2011 | 9.01 | 11.32 | 6.49 |
| 2010 | 8.81 | 11.49 | 6.54 |
| 2009 | 6.91 | 11 | 3.69 |
| 2008 | 4.09 | 7.77 | 1.7 |
| 2007 | 6.02 | 7.77 | 3.92 |