| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.78 | 8.75 | 5.32 |
| 2024 | 8.19 | 10.18 | 6.34 |
| 2023 | 9.28 | 11.53 | 7.87 |
| 2022 | 9.03 | 12.41 | 6.62 |
| 2021 | 13.08 | 17.31 | 10.58 |
| 2020 | 13.36 | 19.22 | 8.35 |
| 2019 | 8.1 | 9.83 | 6.13 |
| 2018 | 8.93 | 11.31 | 7.02 |
| 2017 | 10.9 | 13.92 | 8.82 |
| 2016 | 10.69 | 13.63 | 8.37 |
| 2015 | 10.04 | 16.1 | 6.12 |
| 2014 | 5.81 | 7.71 | 4.53 |
| 2013 | 5.58 | 7.1 | 4.44 |
| 2012 | 5.08 | 6.08 | 4.16 |
| 2011 | 7.55 | 9.37 | 5.88 |
| 2010 | 11.32 | 20.45 | 7.6 |
| 2009 | 15.5 | 25.89 | 10.86 |
| 2008 | 15.13 | 34.44 | 6.85 |
| 2007 | 26.88 | 37.43 | 17 |
| 2006 | 11.18 | 18.68 | 5.51 |
| 2005 | 6.05 | 8.78 | 4.15 |
| 2004 | 7.85 | 13.07 | 4.34 |