| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.57 | 0.78 | 0.42 |
| 2024 | 0.55 | 0.86 | 0.36 |
| 2023 | 0.7 | 1.08 | 0.52 |
| 2022 | 0.63 | 0.93 | 0.5 |
| 2021 | 0.89 | 1.05 | 0.67 |
| 2020 | 1.2 | 1.53 | 1 |
| 2019 | 1.4 | 2 | 1.16 |
| 2018 | 2.56 | 4.27 | 1.29 |
| 2017 | 4.26 | 5.19 | 3.72 |
| 2016 | 4.02 | 5.5 | 3.49 |
| 2015 | 6.48 | 9.85 | 4.93 |
| 2014 | 6.74 | 9.64 | 4.84 |
| 2013 | 9.64 | 11.77 | 7.42 |
| 2012 | 6.67 | 7.89 | 5.37 |
| 2011 | 10.68 | 18.33 | 7.44 |
| 2010 | 12.4 | 16.87 | 9.46 |
| 2009 | 8.71 | 11.02 | 6.72 |
| 2008 | 9.13 | 14.05 | 5.77 |
| 2007 | 11.96 | 17.14 | 7.18 |
| 2006 | 7.25 | 8.98 | 5.7 |
| 2005 | 7.63 | 13.95 | 4.9 |
| 2004 | 27.43 | 68.5 | 12.94 |