| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.38 | 1.75 | 1.13 |
| 2024 | 1.08 | 2.25 | 0.71 |
| 2023 | 1.5 | 1.86 | 1.29 |
| 2022 | 1.72 | 2.11 | 1.39 |
| 2021 | 1.43 | 1.67 | 1.18 |
| 2020 | 2.04 | 2.67 | 1.33 |
| 2019 | 3.64 | 5.94 | 2.34 |
| 2018 | 6.28 | 7.52 | 5.03 |
| 2017 | 5.82 | 11.66 | 3.86 |
| 2016 | 2.72 | 5.37 | 2.26 |
| 2015 | 4.66 | 7.61 | 2.73 |
| 2014 | 2.74 | 3.92 | 1.88 |
| 2013 | 2.12 | 2.73 | 1.6 |
| 2012 | 2.21 | 2.84 | 1.84 |
| 2011 | 3.53 | 4.71 | 2 |
| 2010 | 5.41 | 7.18 | 3.88 |
| 2009 | 3.11 | 4.65 | 1.58 |
| 2008 | 2.3 | 4.1 | 1.11 |
| 2007 | 2.89 | 5.46 | 1.02 |
| 2006 | 1.05 | 1.22 | 0.81 |
| 2005 | 1.06 | 1.43 | 0.77 |
| 2004 | 1.82 | 6.6 | 1.39 |