| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.53 | 2.65 | 2.42 |
| 2024 | 2.44 | 2.85 | 2.11 |
| 2023 | 2.57 | 3 | 2.14 |
| 2022 | 2.88 | 3.78 | 2.5 |
| 2021 | 4.1 | 6.43 | 3.03 |
| 2020 | 4.05 | 5.12 | 3.32 |
| 2019 | 3.47 | 4.19 | 2.8 |
| 2018 | 3.86 | 4.99 | 2.81 |
| 2017 | 3.97 | 4.64 | 3.33 |
| 2016 | 3.2 | 3.58 | 2.84 |
| 2015 | 3.81 | 4.77 | 3.13 |
| 2014 | 3.53 | 4.7 | 3.01 |
| 2013 | 4.5 | 5.45 | 3.45 |
| 2012 | 3.33 | 3.8 | 2.91 |
| 2011 | 4.04 | 4.91 | 3.3 |
| 2010 | 4.82 | 6.31 | 4.1 |
| 2009 | 3.55 | 4.67 | 2.95 |
| 2008 | 3.47 | 5.47 | 2.5 |
| 2007 | 4.84 | 5.99 | 3.86 |
| 2006 | 3.35 | 4.65 | 2.51 |
| 2005 | 2.44 | 3.02 | 1.37 |
| 2004 | 1.78 | 2.53 | 1.31 |