| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 2.3 | 2.5 | 1.97 |
| 2025 | 2.33 | 2.76 | 1.9 |
| 2024 | 2.08 | 2.78 | 1.56 |
| 2023 | 2.49 | 2.7 | 2.19 |
| 2022 | 2.71 | 3.82 | 1.84 |
| 2021 | 4.19 | 5.82 | 3.23 |
| 2020 | 4.08 | 6.08 | 2.89 |
| 2019 | 2.84 | 3.48 | 2.37 |
| 2018 | 3.3 | 4.78 | 2.17 |
| 2017 | 5.33 | 7.73 | 3.86 |
| 2016 | 7.18 | 10.46 | 4.99 |
| 2015 | 7.5 | 15.42 | 4.38 |
| 2014 | 4.65 | 6.14 | 3.57 |
| 2013 | 4.08 | 5.05 | 3.21 |
| 2012 | 3.61 | 5.01 | 2.61 |
| 2011 | 7.78 | 11.7 | 3.96 |
| 2010 | 13.24 | 18.2 | 10.31 |