| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.87 | 42 |
| 2015 | 5.88 | 46 |
| 2014 | 5.92 | 45 |
| 2013 | 5.96 | 45 |
| 2012 | 6 | 46 |
| 2011 | 6.02 | 50 |
| 2010 | 6.04 | 52 |
| 2009 | 6.1 | 54 |
| 2008 | 6.16 | 59 |
| 2007 | 6.2 | 62 |
| 2006 | 6.24 | 64 |
| 2005 | 6.27 | 65 |
| 2004 | 6.34 | 66 |
| 2003 | 6.41 | 66 |
| 2002 | 6.46 | 65 |
| 2001 | 6.5 | 65 |
| 2000 | 6.52 | 66 |
| 1999 | 6.62 | 68 |
| 1998 | 6.7 | 69 |
| 1997 | 6.77 | 73 |
| 1996 | 6.83 | 77 |
| 1995 | 6.86 | 77 |
| 1994 | 6.94 | 77 |
| 1993 | 7 | 78 |
| 1992 | 7.05 | 81 |
| 1991 | 7.08 | 85 |
| 1990 | 7.09 | 87 |
| 1989 | 7.13 | 87 |
| 1988 | 7.16 | 87 |
| 1987 | 7.18 | 88 |
| 1986 | 7.19 | 90 |