| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.65 | 2.17 | 1.36 |
| 2024 | 1.37 | 1.88 | 1.08 |
| 2023 | 2.13 | 3.41 | 1.65 |
| 2022 | 1.71 | 2.5 | 1.18 |
| 2021 | 1.5 | 1.98 | 1.23 |
| 2020 | 2.3 | 3.14 | 1.79 |
| 2019 | 2.38 | 3.15 | 2.04 |
| 2018 | 3.64 | 7.5 | 1.82 |
| 2017 | 6.69 | 9.47 | 4.23 |
| 2016 | 4.74 | 6.66 | 3.83 |
| 2015 | 3.84 | 6.73 | 2.08 |
| 2014 | 1.91 | 2.66 | 1.29 |
| 2013 | 1.21 | 2.05 | 0.83 |
| 2012 | 0.86 | 1.12 | 0.66 |
| 2011 | 1.51 | 2.01 | 0.94 |
| 2010 | 1.5 | 2.04 | 1.06 |
| 2009 | 1.12 | 1.56 | 0.74 |
| 2008 | 0.83 | 1.3 | 0.4 |