| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.8 | 0.93 | 0.71 |
| 2024 | 0.8 | 0.99 | 0.66 |
| 2023 | 0.81 | 0.9 | 0.73 |
| 2022 | 0.82 | 1 | 0.7 |
| 2021 | 1.07 | 1.53 | 0.86 |
| 2020 | 1.21 | 1.4 | 1.08 |
| 2019 | 1.42 | 1.8 | 1.18 |
| 2018 | 1.16 | 1.4 | 0.84 |
| 2017 | 1.7 | 2.69 | 1 |
| 2016 | 5.75 | 10.8 | 2.37 |
| 2015 | 1.6 | 2.37 | 0.98 |
| 2014 | 1.17 | 1.37 | 0.97 |
| 2013 | 1.3 | 1.61 | 0.97 |
| 2012 | 1.04 | 1.33 | 0.86 |