| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.5 | 1.63 | 1.4 |
| 2024 | 1.87 | 2.79 | 1.35 |
| 2023 | 2.71 | 4.18 | 1.88 |
| 2022 | 1.98 | 3.32 | 1.45 |
| 2021 | 1.48 | 1.75 | 1.25 |
| 2020 | 2.02 | 2.48 | 1.49 |
| 2019 | 2.3 | 2.96 | 1.52 |
| 2018 | 2.06 | 2.57 | 1.43 |
| 2017 | 3.09 | 3.73 | 2.41 |
| 2016 | 3.56 | 4.41 | 3 |
| 2015 | 5.52 | 8 | 3.95 |
| 2014 | 6.83 | 8.79 | 5.52 |
| 2013 | 6.94 | 8.09 | 5.29 |
| 2012 | 4.43 | 6.28 | 3.1 |
| 2011 | 5.22 | 6.65 | 4.19 |
| 2010 | 6.5 | 7.92 | 4.49 |
| 2009 | 5.22 | 7.28 | 4.27 |
| 2008 | 6.81 | 11.77 | 3.92 |
| 2007 | 6.05 | 9.62 | 3.25 |
| 2006 | 2.45 | 3.24 | 1.84 |
| 2005 | 2.64 | 4.48 | 1.32 |
| 2004 | 4.94 | 5.64 | 3.19 |
| 2003 | 4.19 | 4.56 | 3.91 |