| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.9 | 1.13 | 0.75 |
| 2024 | 1.13 | 1.74 | 0.78 |
| 2023 | 1.73 | 2.5 | 1.26 |
| 2022 | 1.11 | 1.68 | 0.71 |
| 2021 | 0.76 | 1.04 | 0.6 |
| 2020 | 0.7 | 0.89 | 0.52 |
| 2019 | 0.55 | 0.75 | 0.45 |
| 2018 | 0.82 | 1.12 | 0.47 |
| 2017 | 0.85 | 1.06 | 0.69 |
| 2016 | 1.05 | 1.35 | 0.78 |
| 2015 | 1.31 | 2.6 | 0.85 |
| 2014 | 0.71 | 1.11 | 0.51 |
| 2013 | 0.55 | 0.69 | 0.42 |
| 2012 | 0.47 | 0.56 | 0.37 |
| 2011 | 0.58 | 0.76 | 0.39 |
| 2010 | 0.8 | 1.01 | 0.55 |
| 2009 | 0.61 | 0.9 | 0.41 |
| 2008 | 0.62 | 1.19 | 0.27 |
| 2007 | 0.94 | 1.34 | 0.37 |
| 2006 | 0.33 | 0.41 | 0.26 |
| 2005 | 0.31 | 0.46 | 0.2 |
| 2004 | 0.5 | 1.13 | 0.26 |