| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.13 | 8.3 | 1.61 |
| 2024 | 3.77 | 6.44 | 3.05 |
| 2023 | 4.11 | 4.46 | 3.63 |
| 2022 | 3.89 | 4.82 | 3.17 |
| 2021 | 3.02 | 4.94 | 2.21 |
| 2020 | 2.1 | 3.1 | 1.78 |
| 2019 | 2.31 | 2.92 | 2.01 |
| 2018 | 2.85 | 4.57 | 2.01 |
| 2017 | 6.05 | 10.38 | 4.18 |
| 2016 | 7.53 | 12.27 | 4.32 |
| 2015 | 7.29 | 11.3 | 4.02 |
| 2014 | 3.72 | 8.93 | 1.73 |
| 2013 | 4.95 | 17.38 | 1.8 |
| 2012 | 4.96 | 15.5 | 2.81 |
| 2011 | 4.86 | 6.3 | 2.96 |
| 2010 | 5.96 | 7.52 | 4.27 |
| 2009 | 5.01 | 7.37 | 2.87 |
| 2008 | 5.37 | 11.22 | 2.23 |
| 2007 | 8.91 | 13.5 | 3.52 |
| 2006 | 3.23 | 3.89 | 2.6 |
| 2005 | 2.92 | 3.78 | 1.88 |
| 2004 | 5.8 | 9.61 | 3.52 |