| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.85 | 2.04 | 1.58 |
| 2024 | 1.65 | 2.09 | 1.31 |
| 2023 | 2.12 | 2.29 | 1.98 |
| 2022 | 2.42 | 3.19 | 1.92 |
| 2021 | 2.53 | 2.89 | 2.21 |
| 2020 | 2.82 | 3.95 | 2.36 |
| 2019 | 3.16 | 4.99 | 2.34 |
| 2018 | 3.18 | 4.21 | 2.22 |
| 2017 | 4.61 | 6.22 | 3.92 |
| 2016 | 7.6 | 11.49 | 4.44 |
| 2015 | 8.94 | 15.1 | 5.23 |
| 2014 | 7.92 | 10.23 | 6.04 |
| 2013 | 5.44 | 7.36 | 4.24 |
| 2012 | 5.87 | 7.98 | 4.22 |
| 2011 | 7.97 | 10.61 | 6.13 |
| 2010 | 6.93 | 8.83 | 5.6 |