| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.23 | 7.82 | 5.15 |
| 2024 | 3.76 | 7.81 | 2.42 |
| 2023 | 4.72 | 5.26 | 4.24 |
| 2022 | 4.61 | 5.74 | 3.12 |
| 2021 | 4.18 | 4.76 | 3.74 |
| 2020 | 5.39 | 6.55 | 4.54 |
| 2019 | 5.75 | 8.9 | 3.06 |
| 2018 | 3.52 | 4.92 | 2.4 |
| 2017 | 4.74 | 5.6 | 4.04 |
| 2016 | 6.12 | 7.66 | 5.16 |
| 2015 | 7.12 | 11.46 | 4.05 |
| 2014 | 7.2 | 10.99 | 4.98 |
| 2013 | 4.91 | 6.47 | 3.22 |
| 2012 | 3.48 | 4.37 | 2.87 |
| 2011 | 4.95 | 6.53 | 3.32 |
| 2010 | 5.83 | 7.36 | 4.52 |
| 2009 | 7 | 8.41 | 5.03 |
| 2008 | 7.01 | 12.78 | 2.72 |
| 2007 | 4.77 | 7.98 | 2.39 |
| 2006 | 2.52 | 2.89 | 2.03 |
| 2005 | 2.82 | 4.19 | 2.01 |
| 2004 | 4.07 | 5.37 | 3.17 |
| 2003 | 5.2 | 6.27 | 3.81 |
| 2002 | 6.46 | 8.2 | 4.4 |
| 2001 | 7.61 | 9.35 | 5.48 |
| 2000 | 7.46 | 9.57 | 5.54 |
| 1999 | 4.49 | 6.88 | 2.9 |
| 1998 | 3.55 | 4.8 | 2.9 |
| 1997 | 4.15 | 5.97 | 2.37 |