| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2023 | 4.11 | 4.38 | 3.87 |
| 2022 | 4.67 | 6.09 | 3.61 |
| 2021 | 6.33 | 9.17 | 4.75 |
| 2020 | 5.5 | 7.14 | 4.8 |
| 2019 | 6.05 | 7.06 | 5.05 |
| 2018 | 5.73 | 7.07 | 4.95 |
| 2017 | 6.25 | 6.88 | 5.78 |
| 2016 | 5.86 | 6.38 | 5.37 |
| 2015 | 6.5 | 8.5 | 4.79 |
| 2014 | 4.52 | 6.77 | 3.97 |
| 2013 | 5.84 | 7.93 | 4.44 |
| 2012 | 5.07 | 6.56 | 4.01 |
| 2011 | 7.59 | 10.18 | 5.49 |
| 2010 | 11.08 | 16.89 | 8.22 |
| 2009 | 13.53 | 19.12 | 6.26 |
| 2008 | 11.64 | 23.88 | 5.1 |