| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.08 | 1.22 | 0.85 |
| 2024 | 0.84 | 1.05 | 0.64 |
| 2023 | 0.98 | 1.11 | 0.86 |
| 2022 | 1.17 | 2.02 | 0.88 |
| 2021 | 1.43 | 1.89 | 1.2 |
| 2020 | 1.67 | 2.95 | 1.12 |
| 2019 | 0.96 | 1.68 | 0.69 |
| 2018 | 0.9 | 1.12 | 0.72 |
| 2017 | 1.22 | 1.42 | 1.03 |
| 2016 | 1.4 | 1.73 | 1.26 |
| 2015 | 1.5 | 2.38 | 0.88 |
| 2014 | 0.73 | 1.08 | 0.5 |
| 2013 | 0.67 | 0.98 | 0.49 |
| 2012 | 0.59 | 0.88 | 0.43 |
| 2011 | 1.12 | 2.03 | 0.47 |
| 2010 | 2.17 | 2.97 | 1.68 |
| 2009 | 1.95 | 2.72 | 1.36 |
| 2008 | 1.74 | 2.93 | 0.91 |
| 2007 | 1.88 | 2.84 | 0.72 |
| 2006 | 0.57 | 0.8 | 0.39 |
| 2005 | 0.41 | 0.49 | 0.32 |
| 2004 | 1.2 | 2.26 | 0.47 |