| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.26 | 6.84 | 5.7 |
| 2024 | 4.43 | 7.01 | 3.06 |
| 2023 | 4.24 | 5.56 | 3.35 |
| 2022 | 3.9 | 7.61 | 2.77 |
| 2021 | 4.61 | 5.54 | 3.75 |
| 2020 | 5.68 | 7.01 | 5.08 |
| 2019 | 6.77 | 9.87 | 5.28 |
| 2018 | 7.66 | 12.3 | 4.82 |
| 2017 | 11.64 | 17.89 | 6.16 |
| 2016 | 6.33 | 11.29 | 3.7 |
| 2015 | 10.15 | 15.15 | 5.77 |
| 2014 | 7.62 | 11.55 | 6.52 |
| 2013 | 10 | 13.72 | 7.22 |
| 2012 | 6.53 | 11.67 | 2.11 |
| 2011 | 5.04 | 7.86 | 2.21 |
| 2010 | 6.65 | 9.17 | 5.09 |
| 2009 | 6.52 | 9.24 | 2.76 |
| 2008 | 7.41 | 24.46 | 2.16 |
| 2007 | 18.41 | 26.42 | 7.88 |
| 2006 | 8.11 | 10.61 | 6.48 |
| 2005 | 7.96 | 9.86 | 4.32 |
| 2004 | 6.44 | 10.82 | 4.38 |