| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.59 | 0.83 | 0.53 |
| 2024 | 0.55 | 0.64 | 0.46 |
| 2023 | 0.64 | 0.84 | 0.5 |
| 2022 | 0.7 | 0.88 | 0.61 |
| 2021 | 0.79 | 1.03 | 0.67 |
| 2020 | 0.71 | 0.88 | 0.62 |
| 2019 | 0.89 | 1.13 | 0.78 |
| 2018 | 0.93 | 1.3 | 0.73 |
| 2017 | 1.02 | 1.28 | 0.83 |
| 2016 | 0.85 | 1.05 | 0.73 |
| 2015 | 1.35 | 2.04 | 1 |
| 2014 | 0.76 | 1.4 | 0.57 |
| 2013 | 0.77 | 1 | 0.67 |
| 2012 | 0.97 | 1.26 | 0.7 |
| 2011 | 1.63 | 2.11 | 1.1 |
| 2010 | 1.33 | 1.83 | 1.04 |
| 2009 | 1.49 | 2.1 | 1.13 |
| 2008 | 2.07 | 4.49 | 0.89 |
| 2007 | 3.72 | 5.49 | 2.28 |
| 2006 | 1.87 | 2.71 | 1.26 |
| 2005 | 1.05 | 1.43 | 0.64 |
| 2004 | 0.91 | 1.45 | 0.45 |