| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 6.49 | 64 |
| 2015 | 6.45 | 65 |
| 2014 | 6.39 | 64 |
| 2013 | 6.35 | 64 |
| 2012 | 6.32 | 63 |
| 2011 | 6.28 | 63 |
| 2010 | 6.22 | 60 |
| 2009 | 6.23 | 61 |
| 2008 | 6.2 | 60 |
| 2007 | 6.16 | 58 |
| 2006 | 6.11 | 58 |
| 2005 | 6.05 | 57 |
| 2004 | 6.06 | 55 |
| 2003 | 6.06 | 55 |
| 2002 | 6.06 | 53 |
| 2001 | 6.06 | 53 |
| 2000 | 6.04 | 51 |
| 1999 | 6.02 | 50 |
| 1998 | 5.99 | 46 |
| 1997 | 5.95 | 45 |
| 1996 | 5.9 | 40 |
| 1995 | 5.84 | 40 |
| 1994 | 5.8 | 37 |
| 1993 | 5.77 | 37 |
| 1992 | 5.74 | 38 |
| 1991 | 5.69 | 39 |
| 1990 | 5.64 | 38 |
| 1989 | 5.61 | 34 |
| 1988 | 5.56 | 29 |
| 1987 | 5.51 | 29 |
| 1986 | 5.46 | 30 |