| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.78 | 3.85 | 2 |
| 2024 | 2.2 | 2.67 | 1.73 |
| 2023 | 1.73 | 2.53 | 1.22 |
| 2022 | 1.54 | 2.25 | 0.99 |
| 2021 | 1.62 | 2.19 | 1.29 |
| 2020 | 2.91 | 5.33 | 1.55 |
| 2019 | 2.41 | 3.57 | 2.04 |
| 2018 | 3.15 | 4.2 | 2.01 |
| 2017 | 4.83 | 5.54 | 3.94 |
| 2016 | 4.38 | 5.29 | 3.09 |
| 2015 | 4.79 | 7.1 | 2.88 |
| 2014 | 3.79 | 5.1 | 2.65 |
| 2013 | 2.13 | 2.84 | 1.57 |
| 2012 | 1.9 | 2.56 | 1.35 |
| 2011 | 2.76 | 3.95 | 1.8 |
| 2010 | 2.51 | 3.19 | 1.92 |
| 2009 | 1.98 | 2.67 | 1.18 |
| 2008 | 1.92 | 3.68 | 0.96 |
| 2007 | 2.91 | 4.06 | 1.96 |
| 2006 | 2.11 | 2.81 | 1.8 |
| 2005 | 2.77 | 4.2 | 1.81 |