| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.7 | 0.84 | 0.65 |
| 2024 | 0.67 | 0.85 | 0.51 |
| 2023 | 0.78 | 1.16 | 0.57 |
| 2022 | 1.19 | 1.45 | 0.94 |
| 2021 | 1.55 | 3.07 | 0.79 |
| 2020 | 0.82 | 1.11 | 0.67 |
| 2019 | 0.9 | 1.3 | 0.79 |
| 2018 | 1.28 | 1.92 | 0.83 |
| 2017 | 2.03 | 2.69 | 1.57 |
| 2016 | 1.48 | 2.04 | 1.14 |
| 2015 | 1.48 | 2.32 | 0.87 |
| 2014 | 0.69 | 0.9 | 0.56 |
| 2013 | 0.69 | 0.85 | 0.56 |
| 2012 | 0.65 | 0.86 | 0.49 |
| 2011 | 1.1 | 1.47 | 0.63 |
| 2010 | 1.05 | 1.43 | 0.76 |
| 2009 | 0.95 | 1.49 | 0.48 |
| 2008 | 0.99 | 2 | 0.42 |
| 2007 | 1.19 | 1.73 | 0.47 |
| 2006 | 0.46 | 0.56 | 0.4 |
| 2005 | 0.59 | 0.88 | 0.39 |
| 2004 | 1 | 1.82 | 0.56 |