| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.9 | 0.96 | 0.84 |
| 2024 | 0.95 | 1.24 | 0.76 |
| 2023 | 0.81 | 0.91 | 0.52 |
| 2022 | 0.96 | 1.47 | 0.71 |
| 2021 | 1.23 | 2.31 | 0.69 |
| 2020 | 0.55 | 0.79 | 0.44 |
| 2019 | 0.44 | 0.57 | 0.31 |
| 2018 | 0.47 | 0.79 | 0.31 |
| 2017 | 0.72 | 1.19 | 0.5 |
| 2016 | 0.59 | 0.79 | 0.47 |
| 2015 | 0.67 | 1.01 | 0.44 |
| 2014 | 0.57 | 0.7 | 0.5 |
| 2013 | 0.57 | 0.75 | 0.45 |
| 2012 | 0.8 | 1.09 | 0.57 |
| 2011 | 1.53 | 2.4 | 0.85 |
| 2010 | 1.65 | 2.17 | 1.07 |
| 2009 | 1.5 | 2.16 | 0.84 |
| 2008 | 1.9 | 3.44 | 0.63 |
| 2007 | 2.47 | 3.37 | 1.43 |
| 2006 | 1.49 | 2 | 1.09 |
| 2005 | 0.72 | 1.44 | 0.41 |
| 2004 | 0.8 | 1.16 | 0.59 |