| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.31 | 1.74 | 1.06 |
| 2024 | 0.89 | 1.42 | 0.7 |
| 2023 | 1.2 | 1.47 | 1.06 |
| 2022 | 1.39 | 2.13 | 1.09 |
| 2021 | 1.29 | 1.81 | 0.91 |
| 2020 | 1.29 | 2.6 | 0.85 |
| 2019 | 1.06 | 1.23 | 0.96 |
| 2018 | 1.13 | 1.41 | 0.95 |
| 2017 | 1.65 | 2.01 | 1.3 |
| 2016 | 1.8 | 2.07 | 1.53 |
| 2015 | 2.32 | 3.95 | 1.58 |
| 2014 | 1.45 | 2.06 | 1.17 |
| 2013 | 1.23 | 1.47 | 1.04 |
| 2012 | 1.53 | 2.05 | 1.08 |
| 2011 | 2.74 | 4.43 | 1.7 |
| 2010 | 4.26 | 5.77 | 3.43 |
| 2009 | 4.32 | 5.34 | 3.19 |
| 2008 | 4.31 | 6.34 | 2.64 |