| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.77 | 0.83 | 0.7 |
| 2024 | 0.84 | 1.29 | 0.64 |
| 2023 | 1.27 | 1.92 | 0.91 |
| 2022 | 1.6 | 2.45 | 1.05 |
| 2021 | 2.48 | 3.78 | 1.87 |
| 2020 | 3.74 | 5.19 | 2.59 |
| 2019 | 2.41 | 2.94 | 2.08 |
| 2018 | 3.05 | 3.87 | 2.21 |
| 2017 | 4.85 | 5.88 | 3.54 |
| 2016 | 6.18 | 8.12 | 5.26 |
| 2015 | 11.76 | 23.72 | 5.88 |
| 2014 | 9.8 | 11.87 | 7.62 |
| 2013 | 7.21 | 8.48 | 5.23 |
| 2012 | 5.52 | 6.74 | 4.67 |
| 2011 | 7.66 | 10.7 | 5.22 |
| 2010 | 11.4 | 15.31 | 8.08 |
| 2009 | 11.52 | 14.49 | 9.57 |
| 2008 | 14.46 | 20.79 | 9.27 |
| 2007 | 12.69 | 17.56 | 6.64 |
| 2006 | 4.89 | 6.86 | 3.37 |
| 2005 | 3.39 | 4.17 | 2.54 |