| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.12 | 6.36 | 5.82 |
| 2024 | 6.51 | 7.86 | 5.04 |
| 2023 | 7.62 | 9.31 | 5.57 |
| 2022 | 5.98 | 7.3 | 5.1 |
| 2021 | 7.93 | 9.28 | 6.83 |
| 2020 | 9.88 | 12.91 | 7.54 |
| 2019 | 11.5 | 14.7 | 8.43 |
| 2018 | 15.47 | 20.32 | 9.12 |
| 2017 | 14.89 | 17.01 | 12.98 |
| 2016 | 16.96 | 19.04 | 15.32 |
| 2015 | 16.53 | 25.34 | 11.72 |
| 2014 | 11 | 15.83 | 8.39 |
| 2013 | 12.24 | 16.37 | 7.6 |
| 2012 | 7.9 | 9.41 | 6.78 |
| 2011 | 11.17 | 15.19 | 8.67 |
| 2010 | 11.8 | 17.64 | 8.87 |
| 2009 | 10.4 | 12.06 | 8.64 |
| 2008 | 10.19 | 14.04 | 6.93 |
| 2007 | 11.85 | 17.49 | 8.42 |
| 2006 | 5.37 | 8.28 | 3.42 |
| 2005 | 3.45 | 4.49 | 2.37 |
| 2004 | 4.69 | 7.49 | 3.01 |