| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.33 | 4.34 | 3.04 |
| 2024 | 3.14 | 3.53 | 2.81 |
| 2023 | 3.04 | 3.45 | 2.63 |
| 2022 | 2.65 | 3.11 | 2.48 |
| 2021 | 2.71 | 3.2 | 2.31 |
| 2020 | 3 | 3.46 | 2.51 |
| 2019 | 3.26 | 3.84 | 2.96 |
| 2018 | 3.51 | 4.2 | 2.91 |
| 2017 | 4.14 | 4.76 | 3.72 |
| 2016 | 3.63 | 4.35 | 3.34 |
| 2015 | 4.89 | 8.07 | 3.47 |
| 2014 | 2.6 | 4.28 | 2.2 |
| 2013 | 2.38 | 2.68 | 2.11 |
| 2012 | 2.77 | 3.33 | 2.32 |
| 2011 | 4.35 | 5.43 | 2.94 |
| 2010 | 5.89 | 7.27 | 4.87 |
| 2009 | 4.43 | 5.93 | 3.43 |
| 2008 | 5.66 | 9.91 | 3.37 |
| 2007 | 7.85 | 10.13 | 5.66 |
| 2006 | 5.21 | 6.69 | 3.06 |
| 2005 | 6.09 | 7.72 | 4.1 |
| 2004 | 5.22 | 8.2 | 3.81 |