| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.76 | 0.86 | 0.71 |
| 2024 | 0.83 | 0.96 | 0.61 |
| 2023 | 0.94 | 1.17 | 0.79 |
| 2022 | 1.18 | 1.48 | 0.86 |
| 2021 | 1.38 | 1.81 | 0.97 |
| 2020 | 1.75 | 2.02 | 1.31 |
| 2019 | 1.34 | 1.79 | 0.92 |
| 2018 | 1.14 | 1.49 | 0.95 |
| 2017 | 1.1 | 1.4 | 0.79 |
| 2016 | 0.84 | 1.03 | 0.59 |
| 2015 | 0.94 | 1.43 | 0.7 |
| 2014 | 0.7 | 0.96 | 0.6 |
| 2013 | 0.95 | 1.33 | 0.73 |
| 2012 | 0.98 | 1.27 | 0.73 |
| 2011 | 1.87 | 2.87 | 0.92 |
| 2010 | 1.21 | 1.82 | 0.91 |
| 2009 | 1.39 | 1.67 | 1.07 |
| 2008 | 1.64 | 3.38 | 0.66 |
| 2007 | 1.89 | 3.09 | 0.9 |
| 2006 | 0.71 | 0.92 | 0.6 |
| 2005 | 0.39 | 0.66 | 0.22 |
| 2004 | 0.71 | 1.36 | 0.41 |