| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.84 | 0.92 | 0.78 |
| 2024 | 0.87 | 1.12 | 0.71 |
| 2023 | 0.82 | 0.96 | 0.7 |
| 2022 | 0.82 | 0.95 | 0.67 |
| 2021 | 0.75 | 1.03 | 0.59 |
| 2020 | 0.68 | 0.77 | 0.6 |
| 2019 | 0.76 | 1.03 | 0.65 |
| 2018 | 1.03 | 1.4 | 0.74 |
| 2017 | 1.53 | 1.88 | 1.26 |
| 2016 | 1.46 | 1.83 | 1.17 |
| 2015 | 2.11 | 3.11 | 1.17 |
| 2014 | 0.92 | 1.35 | 0.6 |
| 2013 | 0.74 | 1.05 | 0.51 |
| 2012 | 1.2 | 1.81 | 0.75 |
| 2011 | 2.57 | 3.69 | 1.71 |
| 2010 | 2.79 | 3.88 | 1.68 |
| 2009 | 3.08 | 4.12 | 2.15 |
| 2008 | 4.17 | 7.88 | 1.63 |
| 2007 | 6.2 | 9.08 | 2.9 |
| 2006 | 3.41 | 4.97 | 2.12 |
| 2005 | 2.29 | 3.57 | 1.56 |
| 2004 | 2.97 | 4.85 | 1.97 |