| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.65 | 0.69 | 0.58 |
| 2024 | 0.56 | 1.01 | 0.45 |
| 2023 | 0.71 | 0.85 | 0.6 |
| 2022 | 0.71 | 0.82 | 0.61 |
| 2021 | 0.67 | 0.79 | 0.58 |
| 2020 | 0.71 | 0.92 | 0.62 |
| 2019 | 0.79 | 1.01 | 0.67 |
| 2018 | 0.96 | 1.4 | 0.69 |
| 2017 | 1.77 | 2.81 | 1.39 |
| 2016 | 2.3 | 3.05 | 2.01 |
| 2015 | 4.37 | 7.19 | 2.55 |
| 2014 | 3.99 | 6.44 | 3.21 |
| 2013 | 6.6 | 7.71 | 5.36 |
| 2012 | 5.76 | 7 | 4.69 |
| 2011 | 6.52 | 7.63 | 5.27 |