| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.81 | 4.03 | 3.67 |
| 2024 | 3.98 | 4.94 | 3.26 |
| 2023 | 3.71 | 4.6 | 2.98 |
| 2022 | 3.1 | 3.7 | 2.78 |
| 2021 | 3.42 | 4.78 | 3.03 |
| 2020 | 3.42 | 3.95 | 2.91 |
| 2019 | 4.24 | 6.1 | 3.59 |
| 2018 | 5.47 | 7.6 | 4 |
| 2017 | 6.36 | 9.97 | 4.7 |
| 2016 | 12.24 | 15.74 | 9.19 |
| 2015 | 15.2 | 24.29 | 11.3 |
| 2014 | 7.88 | 13.33 | 6.44 |
| 2013 | 7.34 | 13.42 | 5.06 |
| 2012 | 5.98 | 7.6 | 4.77 |
| 2011 | 11.81 | 22.43 | 5.73 |
| 2010 | 10.92 | 15.18 | 6.05 |
| 2009 | 21.2 | 32.69 | 13.09 |
| 2008 | 16.49 | 26.19 | 7.73 |
| 2007 | 15.58 | 23.3 | 8.14 |
| 2006 | 7.83 | 10.96 | 4.71 |
| 2005 | 4.25 | 5.79 | 2.69 |
| 2004 | 4 | 7.24 | 2.69 |