| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.45 | 2.71 | 1.96 |
| 2024 | 1.77 | 2.98 | 1.32 |
| 2023 | 2.16 | 2.32 | 1.97 |
| 2022 | 2.28 | 2.64 | 2.02 |
| 2021 | 2.37 | 2.85 | 2.16 |
| 2020 | 2.65 | 3.17 | 2.41 |
| 2019 | 2.98 | 4.9 | 2.34 |
| 2018 | 2.94 | 4.18 | 2.05 |
| 2017 | 4.15 | 5.25 | 3.25 |
| 2016 | 4.78 | 6.8 | 3.83 |
| 2015 | 5.36 | 8.91 | 2.97 |
| 2014 | 2.3 | 3.55 | 1.83 |
| 2013 | 2.16 | 2.63 | 1.8 |
| 2012 | 1.97 | 2.84 | 1.4 |
| 2011 | 2.98 | 4.7 | 1.73 |
| 2010 | 3.08 | 3.69 | 2.63 |
| 2009 | 3.12 | 3.98 | 1.63 |
| 2008 | 3.3 | 5.57 | 1.37 |
| 2007 | 4.59 | 7.74 | 1.49 |
| 2006 | 1.17 | 1.62 | 0.84 |
| 2005 | 1.01 | 1.43 | 0.71 |
| 2004 | 1.77 | 2.39 | 1.37 |
| 2003 | 1.83 | 2.07 | 1.67 |
| 2002 | 2.43 | 3.33 | 1.87 |
| 2001 | 3.41 | 4.04 | 2.86 |
| 2000 | 3.26 | 4.18 | 2.44 |
| 1999 | 2.87 | 4.17 | 2.31 |
| 1998 | 5.03 | 6.01 | 3.79 |
| 1997 | 5.26 | 7.9 | 3.06 |