| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.49 | 2.84 | 2.13 |
| 2024 | 2.1 | 3.12 | 1.52 |
| 2023 | 2 | 2.62 | 1.58 |
| 2022 | 1.96 | 2.59 | 1.59 |
| 2021 | 2.03 | 2.44 | 1.84 |
| 2020 | 2.41 | 3.07 | 2.11 |
| 2019 | 2.79 | 4.86 | 2.29 |
| 2018 | 3.29 | 3.99 | 2.88 |
| 2017 | 4.65 | 6.52 | 3.32 |
| 2016 | 5.73 | 9.22 | 4.87 |
| 2015 | 8.73 | 17.58 | 3.93 |
| 2014 | 3.67 | 4.74 | 2.89 |
| 2013 | 2.83 | 3.89 | 2.11 |
| 2012 | 2.27 | 2.81 | 1.62 |
| 2011 | 4.3 | 6.23 | 2.28 |
| 2010 | 7.69 | 15.22 | 4.13 |
| 2009 | 7.28 | 10.52 | 5.74 |