| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.03 | 1.14 | 0.91 |
| 2024 | 1.03 | 1.35 | 0.87 |
| 2023 | 0.95 | 1.18 | 0.67 |
| 2022 | 0.82 | 1.09 | 0.66 |
| 2021 | 0.81 | 1.14 | 0.63 |
| 2020 | 0.69 | 0.94 | 0.54 |
| 2019 | 0.61 | 0.79 | 0.51 |
| 2018 | 0.88 | 1.3 | 0.57 |
| 2017 | 1.88 | 2.73 | 1.26 |
| 2016 | 1.8 | 2.48 | 1.42 |
| 2015 | 3.07 | 4.74 | 1.07 |
| 2014 | 0.72 | 1.35 | 0.43 |
| 2013 | 0.41 | 0.47 | 0.35 |
| 2012 | 0.37 | 0.45 | 0.31 |
| 2011 | 0.65 | 0.91 | 0.35 |
| 2010 | 0.85 | 1.37 | 0.58 |
| 2009 | 0.68 | 1.26 | 0.29 |
| 2008 | 0.66 | 1.38 | 0.22 |
| 2007 | 1.07 | 1.82 | 0.49 |
| 2006 | 0.53 | 0.64 | 0.45 |
| 2005 | 0.62 | 1.03 | 0.4 |
| 2004 | 0.85 | 1.55 | 0.58 |