| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.29 | 2.51 | 2.18 |
| 2024 | 2.33 | 2.83 | 1.85 |
| 2023 | 3.35 | 4.61 | 2.43 |
| 2022 | 4.04 | 5.41 | 2.52 |
| 2021 | 3.39 | 5.84 | 1.64 |
| 2020 | 1.72 | 2.28 | 1.42 |
| 2019 | 2.03 | 2.54 | 1.59 |
| 2018 | 2.49 | 3.19 | 1.58 |
| 2017 | 2.54 | 2.85 | 2.09 |
| 2016 | 2.29 | 2.88 | 1.67 |
| 2015 | 2.2 | 3.5 | 1.47 |
| 2014 | 1.63 | 2.09 | 1.34 |
| 2013 | 1.33 | 1.62 | 1.08 |
| 2012 | 1.61 | 2.15 | 1.19 |
| 2011 | 2.66 | 3.34 | 1.64 |
| 2010 | 3.69 | 5.56 | 2.58 |
| 2009 | 4.51 | 6.37 | 2.95 |
| 2008 | 5.49 | 10.65 | 2.31 |
| 2007 | 8.95 | 11.78 | 6.41 |