| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 6.73 | 92 |
| 2015 | 6.58 | 92 |
| 2014 | 6.53 | 91 |
| 2013 | 6.53 | 88 |
| 2012 | 6.59 | 86 |
| 2011 | 6.64 | 85 |
| 2010 | 6.67 | 85 |
| 2009 | 6.72 | 83 |
| 2008 | 6.74 | 82 |
| 2007 | 6.74 | 80 |
| 2006 | 6.73 | 79 |
| 2005 | 6.72 | 77 |
| 2004 | 6.6 | 76 |
| 2003 | 6.52 | 77 |
| 2002 | 6.5 | 75 |
| 2001 | 6.52 | 74 |
| 2000 | 6.58 | 72 |
| 1999 | 6.82 | 70 |
| 1998 | 7.08 | 64 |
| 1997 | 7.35 | 60 |
| 1996 | 7.6 | 58 |
| 1995 | 7.79 | 57 |
| 1994 | 7.81 | 57 |
| 1993 | 7.76 | 56 |
| 1992 | 7.66 | 55 |
| 1991 | 7.55 | 54 |
| 1990 | 7.47 | 55 |
| 1989 | 7.09 | 55 |
| 1988 | 6.77 | 57 |
| 1987 | 6.49 | 57 |
| 1986 | 6.23 | 58 |