| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0 | ||
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 0 | ||
| 2021 | 0 | ||
| 2020 | 1.54 | 1.57 | 1.48 |
| 2019 | 4.73 | 5.53 | 2.91 |
| 2018 | 4.08 | 6.57 | 1.46 |
| 2017 | 3.51 | 5.39 | 2.78 |
| 2016 | 6.56 | 10.44 | 3.31 |
| 2015 | 11.14 | 19.26 | 5.19 |
| 2014 | 11.84 | 25.46 | 4.28 |
| 2013 | 15.56 | 29.98 | 7.08 |
| 2012 | 11.94 | 23.97 | 5.43 |
| 2011 | 17.12 | 29.25 | 11.63 |