| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.93 | 2.84 | 1.49 |
| 2024 | 1.39 | 1.92 | 0.93 |
| 2023 | 1.73 | 2.3 | 1.25 |
| 2022 | 2.72 | 4.96 | 1.82 |
| 2021 | 4.42 | 5.66 | 3.6 |
| 2020 | 4.34 | 5.56 | 3.35 |
| 2019 | 4.42 | 5.44 | 3.26 |
| 2018 | 6.41 | 9.15 | 3.64 |
| 2017 | 6.5 | 9.18 | 4.42 |
| 2016 | 4.91 | 5.46 | 4.27 |
| 2015 | 6.02 | 9.88 | 4.26 |
| 2014 | 4.78 | 5.9 | 3.91 |
| 2013 | 3.64 | 4.63 | 2.61 |
| 2012 | 2.68 | 3.59 | 2.01 |
| 2011 | 4.96 | 7.66 | 2.5 |
| 2010 | 4.49 | 6.78 | 3.54 |
| 2009 | 3 | 3.99 | 2.09 |
| 2008 | 7.13 | 12.84 | 1.62 |
| 2007 | 13.59 | 22.91 | 9.34 |
| 2006 | 6.71 | 10.48 | 3.93 |
| 2005 | 4.29 | 5.8 | 3.06 |