| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.67 | 1.83 | 1.49 |
| 2024 | 1.84 | 2.18 | 1.46 |
| 2023 | 4.28 | 8 | 1.55 |
| 2022 | 2.39 | 3.1 | 1.92 |
| 2021 | 1.7 | 4.08 | 1.11 |
| 2020 | 1.25 | 2.79 | 0.79 |
| 2019 | 1.02 | 1.32 | 0.83 |
| 2018 | 1 | 1.3 | 0.83 |
| 2017 | 1.46 | 2.07 | 1.05 |
| 2016 | 2.68 | 4.74 | 1.89 |
| 2015 | 4.19 | 8.08 | 2.51 |
| 2014 | 2.33 | 2.93 | 1.66 |
| 2013 | 4.13 | 9.31 | 1.78 |
| 2012 | 5.39 | 7.74 | 3.73 |
| 2011 | 6.86 | 8.17 | 5.12 |
| 2010 | 6.19 | 8.3 | 4.53 |
| 2009 | 5.4 | 7.94 | 3.08 |
| 2008 | 3.65 | 7.16 | 1.42 |
| 2007 | 6.12 | 8.03 | 4.32 |