| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 7.47 | 10.28 | 6.28 |
| 2024 | 5.99 | 9.36 | 4.53 |
| 2023 | 7.93 | 9.35 | 7.08 |
| 2022 | 8.08 | 11.72 | 5.82 |
| 2021 | 7.76 | 9.29 | 6.35 |
| 2020 | 10.68 | 15.98 | 7.67 |
| 2019 | 10.98 | 13.75 | 7.65 |
| 2018 | 10.56 | 15.27 | 7.9 |
| 2017 | 15.53 | 20.75 | 11.87 |
| 2016 | 19.68 | 27.49 | 15.94 |
| 2015 | 21.12 | 37.32 | 10.16 |
| 2014 | 10.57 | 12.49 | 8.68 |
| 2013 | 12.59 | 15.51 | 10.16 |
| 2012 | 17.01 | 23 | 8.95 |
| 2011 | 22.87 | 37.41 | 14.68 |
| 2010 | 25.94 | 38.9 | 17.9 |
| 2009 | 19.97 | 29.05 | 11.35 |
| 2008 | 20.48 | 30.32 | 8.31 |
| 2007 | 22.88 | 29.24 | 5.68 |