| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.26 | 2.72 | 1.83 |
| 2024 | 1.95 | 2.38 | 1.61 |
| 2023 | 2.06 | 2.58 | 1.59 |
| 2022 | 2.29 | 3.29 | 1.78 |
| 2021 | 4.37 | 7.61 | 2.87 |
| 2020 | 3.93 | 5.56 | 2.87 |
| 2019 | 2.9 | 3.72 | 2.04 |
| 2018 | 2.45 | 3.04 | 2 |
| 2017 | 2.47 | 2.89 | 2.03 |
| 2016 | 1.82 | 2.24 | 1.55 |
| 2015 | 2.73 | 4.56 | 1.89 |
| 2014 | 1.84 | 3.09 | 1.52 |
| 2013 | 2.75 | 4.27 | 1.99 |
| 2012 | 4.33 | 6.03 | 2.51 |
| 2011 | 8.91 | 13.75 | 4.59 |
| 2010 | 7.47 | 12.08 | 4.3 |
| 2009 | 6.95 | 8.88 | 3.93 |
| 2008 | 6.96 | 13.33 | 2.91 |
| 2007 | 11.57 | 18.36 | 5.87 |
| 2006 | 2.73 | 6.2 | 1.33 |
| 2005 | 1.89 | 2.92 | 1.27 |
| 2004 | 2.98 | 4.59 | 2.22 |