| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.05 | 5.79 | 4.53 |
| 2024 | 4.16 | 6.75 | 3.09 |
| 2023 | 4.29 | 5.68 | 3.71 |
| 2022 | 3.79 | 5.72 | 2.8 |
| 2021 | 3.76 | 4.32 | 3.35 |
| 2020 | 4.93 | 7.62 | 3.89 |
| 2019 | 4.53 | 7.4 | 2.93 |
| 2018 | 3.8 | 5.43 | 2.46 |
| 2017 | 6 | 8.89 | 5 |
| 2016 | 6.13 | 7.41 | 4.99 |
| 2015 | 7.05 | 15.01 | 3.91 |
| 2014 | 3.27 | 4.51 | 2.6 |
| 2013 | 2.95 | 4.05 | 2.3 |
| 2012 | 3.33 | 3.89 | 2.33 |
| 2011 | 3.92 | 4.07 | 3.56 |
| 2010 | 4.6 | 5.51 | 3.67 |
| 2009 | 2.92 | 5.57 | 1.27 |
| 2008 | 2.78 | 6.83 | 1.01 |
| 2007 | 4.58 | 7.58 | 1.8 |
| 2006 | 1.82 | 2.19 | 1.36 |
| 2005 | 1.51 | 2.07 | 0.87 |
| 2004 | 3.17 | 5.74 | 1.86 |
| 2003 | 4.67 | 6.44 | 3.57 |
| 2002 | 5.64 | 8.65 | 2.37 |
| 2001 | 4.67 | 5.87 | 3.35 |
| 2000 | 8.08 | 16.2 | 5.12 |
| 1999 | 8.84 | 12.09 | 5.15 |
| 1998 | 8.11 | 10.51 | 5.32 |
| 1997 | 6.92 | 10.56 | 3.85 |