| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.51 | 4.12 | 3 |
| 2024 | 3.07 | 3.7 | 2.32 |
| 2023 | 2.63 | 3.85 | 1.52 |
| 2022 | 2 | 3.09 | 1.46 |
| 2021 | 3.4 | 4.2 | 2.78 |
| 2020 | 4.35 | 5.39 | 3.72 |
| 2019 | 3.23 | 4.4 | 2.25 |
| 2018 | 3.1 | 4.19 | 2.01 |
| 2017 | 4 | 4.55 | 3.36 |
| 2016 | 5.6 | 7.95 | 4.36 |
| 2015 | 5.95 | 9.85 | 3.57 |
| 2014 | 4.42 | 5.51 | 3.23 |
| 2013 | 3.39 | 4.06 | 2.69 |
| 2012 | 2.92 | 3.83 | 2.16 |
| 2011 | 3.68 | 4.8 | 2.4 |
| 2010 | 4.44 | 5.73 | 3.62 |
| 2009 | 2.84 | 4.71 | 1.51 |
| 2008 | 2.82 | 5.83 | 1.14 |
| 2007 | 4.33 | 6.11 | 2.49 |
| 2006 | 2.71 | 3.65 | 2.14 |
| 2005 | 2.89 | 3.82 | 2.08 |
| 2004 | 5 | 9.21 | 2.58 |