| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.66 | 6.61 | 4.85 |
| 2024 | 5.81 | 7.97 | 4 |
| 2023 | 7.09 | 8.89 | 6.12 |
| 2022 | 5.74 | 8.82 | 4.55 |
| 2021 | 4.85 | 6.97 | 3.38 |
| 2020 | 3.65 | 7.05 | 2.41 |
| 2019 | 2.85 | 3.48 | 2.22 |
| 2018 | 2.51 | 3.59 | 1.79 |
| 2017 | 4.06 | 5.47 | 3.24 |
| 2016 | 4.29 | 6.22 | 3.26 |
| 2015 | 3.6 | 5.98 | 2.27 |
| 2014 | 1.91 | 2.5 | 1.48 |
| 2013 | 1.57 | 1.95 | 1.29 |
| 2012 | 1.62 | 2.02 | 1.22 |
| 2011 | 2.44 | 3.16 | 1.38 |
| 2010 | 2.26 | 3.44 | 1.55 |
| 2009 | 1.68 | 2.26 | 0.92 |
| 2008 | 2 | 3.57 | 0.64 |
| 2007 | 2.52 | 3.7 | 1.15 |
| 2006 | 1.13 | 1.5 | 0.77 |
| 2005 | 0.9 | 1.29 | 0.7 |
| 2004 | 1.88 | 3.88 | 1.04 |