| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.03 | 1.14 | 0.93 |
| 2024 | 0.64 | 1.02 | 0.46 |
| 2023 | 0.67 | 0.78 | 0.59 |
| 2022 | 0.63 | 1.06 | 0.39 |
| 2021 | 0.39 | 0.47 | 0.33 |
| 2020 | 0.44 | 0.77 | 0.34 |
| 2019 | 0.43 | 0.57 | 0.35 |
| 2018 | 0.54 | 0.71 | 0.46 |
| 2017 | 0.76 | 0.95 | 0.64 |
| 2016 | 0.83 | 1.04 | 0.62 |
| 2015 | 0.86 | 1.55 | 0.51 |
| 2014 | 0.42 | 0.62 | 0.31 |
| 2013 | 0.38 | 0.49 | 0.31 |
| 2012 | 0.46 | 0.57 | 0.38 |
| 2011 | 0.83 | 1.24 | 0.44 |
| 2010 | 1.04 | 1.26 | 0.75 |
| 2009 | 1.01 | 1.29 | 0.62 |
| 2008 | 0.73 | 1.22 | 0.4 |
| 2007 | 0.91 | 1.2 | 0.71 |