| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.77 | 0.96 | 0.5 |
| 2024 | 0.48 | 0.65 | 0.37 |
| 2023 | 0.47 | 0.58 | 0.42 |
| 2022 | 0.48 | 0.57 | 0.4 |
| 2021 | 0.49 | 0.58 | 0.39 |
| 2020 | 0.53 | 0.72 | 0.34 |
| 2019 | 0.36 | 0.46 | 0.28 |
| 2018 | 0.42 | 0.68 | 0.27 |
| 2017 | 0.89 | 1.47 | 0.61 |
| 2016 | 0.82 | 1.01 | 0.67 |
| 2015 | 0.95 | 1.72 | 0.59 |
| 2014 | 0.61 | 0.99 | 0.41 |
| 2013 | 0.5 | 0.61 | 0.44 |
| 2012 | 0.7 | 1.07 | 0.42 |
| 2011 | 1.37 | 1.98 | 0.75 |
| 2010 | 1.6 | 2.11 | 1.25 |
| 2009 | 1.6 | 2.01 | 0.69 |
| 2008 | 1.2 | 2.34 | 0.49 |
| 2007 | 1.98 | 3.19 | 0.91 |
| 2006 | 0.91 | 1.19 | 0.68 |
| 2005 | 1.01 | 1.34 | 0.8 |
| 2004 | 1.92 | 3.2 | 1.08 |