| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.6 | 7.17 | 3.61 |
| 2024 | 2.6 | 4.49 | 1.74 |
| 2023 | 2.17 | 3.34 | 1.71 |
| 2022 | 3.42 | 8.28 | 1.68 |
| 2021 | 7.6 | 9.05 | 6.64 |
| 2020 | 6.4 | 13.26 | 4.37 |
| 2019 | 5.63 | 6.91 | 4.81 |
| 2018 | 6.15 | 8.44 | 4.25 |
| 2017 | 9.96 | 12.53 | 7.95 |
| 2016 | 9.41 | 11.67 | 7.94 |
| 2015 | 12.85 | 23.44 | 8.65 |
| 2014 | 6.94 | 10.29 | 5.75 |
| 2013 | 6.55 | 7.57 | 5.75 |
| 2012 | 6.77 | 8.96 | 5.39 |
| 2011 | 9.28 | 12.54 | 6.45 |
| 2010 | 15.02 | 19.72 | 11.26 |
| 2009 | 13.86 | 18.87 | 9.32 |
| 2008 | 17.03 | 30.78 | 7.77 |
| 2007 | 21.18 | 32.92 | 7.93 |
| 2006 | 8 | 9.52 | 6.99 |
| 2005 | 11.26 | 14.17 | 1.75 |
| 2004 | 2.84 | 4.04 | 2.23 |