| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.2 | 3.37 | 2.94 |
| 2024 | 3.49 | 4.48 | 2.5 |
| 2023 | 5.18 | 6.18 | 3.68 |
| 2022 | 5.09 | 6.5 | 3.61 |
| 2021 | 7.05 | 11.87 | 4.57 |
| 2020 | 9.56 | 14.01 | 6.42 |
| 2019 | 7.08 | 8.35 | 5.34 |
| 2018 | 5.68 | 6.58 | 4.45 |
| 2017 | 4.53 | 5.8 | 3.62 |
| 2016 | 3.78 | 4.59 | 3.03 |
| 2015 | 5.15 | 6.6 | 3.31 |
| 2014 | 3.48 | 4.67 | 2.98 |
| 2013 | 3.3 | 4.6 | 1.97 |
| 2012 | 2.25 | 2.95 | 1.75 |
| 2011 | 3.86 | 5.81 | 2.06 |
| 2010 | 6.6 | 8.83 | 4.79 |
| 2009 | 7.22 | 10.3 | 2.41 |
| 2008 | 3.66 | 5.84 | 1.96 |
| 2007 | 5.16 | 8.54 | 2.64 |
| 2006 | 2.62 | 3.6 | 1.52 |
| 2005 | 1.36 | 1.74 | 0.87 |
| 2004 | 1.75 | 2.36 | 1.16 |