| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 8.76 | 9.79 | 7.62 |
| 2023 | 9.06 | 9.85 | 8.01 |
| 2022 | 9.21 | 10.08 | 8.04 |
| 2021 | 8.15 | 9.32 | 7.15 |
| 2020 | 8.14 | 9.48 | 7.17 |
| 2019 | 7.41 | 8.31 | 6.45 |
| 2018 | 7.03 | 7.72 | 6.02 |
| 2017 | 6.73 | 7.72 | 5.88 |
| 2016 | 9.2 | 12.47 | 6.37 |
| 2015 | 8.21 | 9.57 | 6.1 |
| 2014 | 4.83 | 7.24 | 3.84 |
| 2013 | 4.57 | 5.14 | 4.09 |
| 2012 | 5.07 | 5.63 | 4.16 |
| 2011 | 5.44 | 6.47 | 4.47 |
| 2010 | 11.09 | 16.62 | 5.8 |
| 2009 | 15.17 | 17.14 | 13.46 |
| 2008 | 16.34 | 22.51 | 12.59 |
| 2007 | 19.29 | 28.65 | 11.06 |
| 2006 | 7.86 | 11.29 | 6.72 |
| 2005 | 9.96 | 11.49 | 8.22 |
| 2004 | 15.34 | 24.63 | 11.11 |