| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.32 | 2.62 | 1.95 |
| 2024 | 2.02 | 3.03 | 0.98 |
| 2023 | 1.39 | 2.42 | 0.87 |
| 2022 | 0.86 | 1.52 | 0.5 |
| 2021 | 0.55 | 1 | 0.3 |
| 2020 | 0.64 | 0.87 | 0.43 |
| 2019 | 0.83 | 1.12 | 0.63 |
| 2018 | 3.2 | 8.05 | 0.63 |
| 2017 | 8.01 | 9.26 | 6.95 |
| 2016 | 6.21 | 9.23 | 5.29 |
| 2015 | 8.77 | 12.93 | 7.36 |
| 2014 | 6.47 | 9.87 | 4.86 |
| 2013 | 6.17 | 7.03 | 5.14 |
| 2012 | 6.29 | 7.83 | 4.41 |
| 2011 | 9.94 | 16.44 | 5.77 |
| 2010 | 18.99 | 26.75 | 15.93 |