| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.42 | 1.54 | 1.31 |
| 2024 | 1.6 | 1.74 | 1.38 |
| 2023 | 1.61 | 1.89 | 1.45 |
| 2022 | 1.49 | 1.95 | 1.27 |
| 2021 | 1.89 | 2.1 | 1.63 |
| 2020 | 2.85 | 5.24 | 1.87 |
| 2019 | 3.53 | 4.84 | 2.6 |
| 2018 | 7.92 | 8.73 | 2.89 |
| 2017 | 8.42 | 9.78 | 7.78 |
| 2016 | 9.66 | 10.7 | 8.87 |
| 2015 | 11.47 | 18.76 | 8.01 |
| 2014 | 16.83 | 31.8 | 11.18 |
| 2013 | 11.45 | 23.61 | 7.22 |
| 2012 | 7.33 | 9.26 | 6.32 |
| 2011 | 9.17 | 12.66 | 6.82 |
| 2010 | 10.49 | 14.81 | 7.64 |
| 2009 | 6.28 | 8.4 | 5.16 |
| 2008 | 13.01 | 24.1 | 4.08 |