| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.68 | 2.9 | 2.54 |
| 2024 | 2.85 | 3.37 | 2.41 |
| 2023 | 3.03 | 3.66 | 2.55 |
| 2022 | 2.96 | 4.08 | 2.46 |
| 2021 | 3.47 | 4.74 | 2.69 |
| 2020 | 3.25 | 4.46 | 2.5 |
| 2019 | 3.04 | 3.48 | 2.51 |
| 2018 | 3.3 | 4.38 | 2.5 |
| 2017 | 4.53 | 5.38 | 4.13 |
| 2016 | 4.47 | 5.28 | 3.66 |
| 2015 | 5.74 | 10.3 | 4.06 |
| 2014 | 4 | 5 | 3.35 |
| 2013 | 4.14 | 4.77 | 3.65 |
| 2012 | 4.31 | 4.92 | 3.23 |
| 2011 | 5.88 | 7.42 | 4.84 |
| 2010 | 6.68 | 7.88 | 4.53 |
| 2009 | 4.53 | 7.15 | 2.81 |
| 2008 | 3.38 | 6.71 | 2.01 |
| 2007 | 5.01 | 6.72 | 2.78 |
| 2006 | 2.51 | 3.07 | 2.02 |
| 2005 | 2.26 | 2.68 | 2 |