| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.69 | 0.75 | 0.63 |
| 2024 | 0.62 | 0.85 | 0.52 |
| 2023 | 0.73 | 0.87 | 0.67 |
| 2022 | 0.69 | 0.82 | 0.62 |
| 2021 | 0.74 | 0.9 | 0.63 |
| 2020 | 0.69 | 0.79 | 0.61 |
| 2019 | 0.84 | 1.05 | 0.71 |
| 2018 | 1.07 | 1.35 | 0.78 |
| 2017 | 1.39 | 1.57 | 1.15 |
| 2016 | 1.54 | 1.89 | 1.27 |
| 2015 | 2.19 | 4.83 | 1.3 |
| 2014 | 1.4 | 1.87 | 1.11 |
| 2013 | 1.61 | 2.44 | 1.16 |
| 2012 | 4.33 | 6.72 | 1.82 |
| 2011 | 5.76 | 6.41 | 4.88 |
| 2010 | 6.09 | 7.23 | 4.94 |
| 2009 | 3.67 | 5.11 | 2.63 |
| 2008 | 5.89 | 14.45 | 2.15 |
| 2007 | 9.41 | 12.9 | 5.56 |
| 2006 | 3.51 | 6.44 | 2.02 |
| 2005 | 2.33 | 2.66 | 1.94 |