| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.82 | 4.76 | 1.95 |
| 2024 | 1.7 | 2.71 | 1.09 |
| 2023 | 1.53 | 1.81 | 1.2 |
| 2022 | 1.15 | 1.69 | 0.79 |
| 2021 | 1 | 1.21 | 0.89 |
| 2020 | 1.07 | 1.39 | 0.83 |
| 2019 | 1.02 | 1.47 | 0.81 |
| 2018 | 1.27 | 2 | 0.83 |
| 2017 | 1.79 | 2.31 | 1.39 |
| 2016 | 1.91 | 2.65 | 1.48 |
| 2015 | 2.85 | 5.18 | 1.55 |
| 2014 | 1.78 | 2.79 | 1.26 |
| 2013 | 1.26 | 1.62 | 1.06 |
| 2012 | 1.34 | 1.66 | 1.07 |
| 2011 | 1.96 | 2.57 | 1.33 |
| 2010 | 2.52 | 3.47 | 1.74 |
| 2009 | 2.61 | 3.96 | 0.97 |
| 2008 | 2.41 | 4.74 | 0.85 |
| 2007 | 2.64 | 4.24 | 1.14 |
| 2006 | 1.16 | 1.42 | 1.02 |
| 2005 | 1.37 | 3.07 | 0.94 |
| 2004 | 1.81 | 2.79 | 1.24 |
| 2003 | 2.87 | 3.25 | 2.3 |
| 2002 | 2.8 | 3.44 | 1.63 |
| 2001 | 4.84 | 5.74 | 3.94 |
| 2000 | 3.94 | 4.91 | 2.92 |
| 1999 | 3.46 | 4.49 | 2.89 |
| 1998 | 3.63 | 4.56 | 2.99 |
| 1997 | 4.76 | 6.97 | 3.34 |