| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.82 | 2.35 | 1.43 |
| 2024 | 1.4 | 1.68 | 1.07 |
| 2023 | 1.8 | 2.36 | 1.35 |
| 2022 | 2.33 | 3.54 | 1.78 |
| 2021 | 2.72 | 3.83 | 1.92 |
| 2020 | 2.51 | 3.76 | 2.06 |
| 2019 | 2.24 | 3.37 | 1.57 |
| 2018 | 2.1 | 2.86 | 1.43 |
| 2017 | 3.86 | 5.23 | 2.69 |
| 2016 | 4.64 | 6.34 | 3.15 |
| 2015 | 4.57 | 8.62 | 2.78 |
| 2014 | 2.69 | 3.23 | 2.3 |
| 2013 | 2.17 | 2.77 | 1.73 |
| 2012 | 1.94 | 2.39 | 1.59 |
| 2011 | 2.82 | 3.62 | 1.88 |
| 2010 | 3.7 | 4.44 | 2.67 |
| 2009 | 3.29 | 5.2 | 2.05 |
| 2008 | 3.91 | 6.87 | 1.63 |
| 2007 | 6.3 | 9.48 | 3.78 |
| 2006 | 4.58 | 7.18 | 2.32 |
| 2005 | 4.85 | 6.49 | 4.14 |
| 2004 | 7.41 | 12.66 | 4.94 |