| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.46 | 7.04 | 5.66 |
| 2024 | 5.49 | 8.56 | 4.28 |
| 2023 | 4.75 | 5.66 | 3.91 |
| 2022 | 4.05 | 5.3 | 3.39 |
| 2021 | 5.54 | 7.91 | 4.38 |
| 2020 | 7.55 | 8.63 | 5.71 |
| 2019 | 11.72 | 16.27 | 6.79 |
| 2018 | 10.08 | 12.29 | 8.55 |
| 2017 | 8.61 | 10.55 | 7.43 |
| 2016 | 6.61 | 8.33 | 5.25 |
| 2015 | 14.34 | 26.36 | 5.72 |
| 2014 | 12.82 | 24.72 | 9.58 |
| 2013 | 17.5 | 22.12 | 14.2 |
| 2012 | 13.74 | 18.78 | 7.97 |
| 2011 | 8.58 | 10.68 | 6.93 |
| 2010 | 8.64 | 13.93 | 5.78 |
| 2009 | 12.25 | 19.41 | 7.06 |
| 2008 | 9.4 | 20.84 | 5.34 |
| 2007 | 30.46 | 50.86 | 16.9 |
| 2006 | 33.78 | 61.64 | 16.49 |
| 2005 | 23.99 | 30.62 | 15.74 |
| 2004 | 27.74 | 43.19 | 20.74 |