| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.34 | 0.62 | 0.19 |
| 2024 | 0.39 | 0.45 | 0.34 |
| 2023 | 0.48 | 0.52 | 0.42 |
| 2022 | 0.52 | 0.65 | 0.44 |
| 2021 | 0.79 | 1.19 | 0.6 |
| 2020 | 0.53 | 0.69 | 0.44 |
| 2019 | 0.56 | 0.77 | 0.48 |
| 2018 | 0.84 | 1.33 | 0.5 |
| 2017 | 1.12 | 1.47 | 0.88 |
| 2016 | 0.81 | 1.02 | 0.67 |
| 2015 | 0.82 | 1.33 | 0.61 |
| 2014 | 0.46 | 0.65 | 0.4 |
| 2013 | 0.44 | 0.53 | 0.37 |
| 2012 | 0.49 | 0.63 | 0.38 |
| 2011 | 0.81 | 1.05 | 0.53 |
| 2010 | 1.05 | 1.36 | 0.82 |
| 2009 | 1.09 | 1.48 | 0.66 |
| 2008 | 1.4 | 2.43 | 0.55 |
| 2007 | 1.42 | 2.29 | 0.61 |
| 2006 | 0.65 | 0.92 | 0.48 |
| 2005 | 0.58 | 0.76 | 0.41 |
| 2004 | 0.68 | 1.14 | 0.5 |