| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.52 | 2.96 | 2.35 |
| 2024 | 2.44 | 3.25 | 1.86 |
| 2023 | 2.84 | 3.78 | 2.28 |
| 2022 | 2.91 | 4.13 | 2.26 |
| 2021 | 2.74 | 3.08 | 2.36 |
| 2020 | 3.33 | 4.48 | 2.85 |
| 2019 | 3.17 | 4.36 | 2.73 |
| 2018 | 3.45 | 4.49 | 2.57 |
| 2017 | 5.32 | 6.73 | 4.2 |
| 2016 | 5.32 | 7.1 | 4.18 |
| 2015 | 6.27 | 11.62 | 3.69 |
| 2014 | 4.4 | 5.56 | 3.32 |
| 2013 | 3.67 | 4.71 | 3 |
| 2012 | 3.91 | 4.9 | 3.17 |
| 2011 | 5.07 | 6.77 | 3.77 |
| 2010 | 4.94 | 6.15 | 3.42 |
| 2009 | 3.77 | 4.82 | 2.73 |
| 2008 | 3.74 | 7.8 | 1.83 |
| 2007 | 5.27 | 8.31 | 2.77 |
| 2006 | 2.97 | 4.07 | 2.47 |
| 2005 | 3 | 3.78 | 2.22 |
| 2004 | 5.16 | 8.25 | 3.57 |
| 2003 | 6.94 | 8.86 | 4.34 |
| 2002 | 9.69 | 16.64 | 7.41 |
| 2001 | 0 | -1.59 | |
| 2000 | 0 | -1.65 | |
| 1999 | 12.7 | 16.34 | 10.46 |
| 1998 | 4.04 | 6.01 | 2.71 |
| 1997 | 7.35 | 15.35 | 3.55 |