| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.6 | 80 |
| 2015 | 7.51 | 79 |
| 2014 | 7.47 | 79 |
| 2013 | 7.47 | 79 |
| 2012 | 7.48 | 81 |
| 2011 | 7.49 | 81 |
| 2010 | 7.47 | 84 |
| 2009 | 7.49 | 84 |
| 2008 | 7.48 | 83 |
| 2007 | 7.44 | 83 |
| 2006 | 7.39 | 80 |
| 2005 | 7.34 | 80 |
| 2004 | 7.35 | 80 |
| 2003 | 7.36 | 82 |
| 2002 | 7.36 | 83 |
| 2001 | 7.35 | 85 |
| 2000 | 7.33 | 86 |
| 1999 | 7.37 | 86 |
| 1998 | 7.41 | 86 |
| 1997 | 7.44 | 87 |
| 1996 | 7.46 | 89 |
| 1995 | 7.47 | 91 |
| 1994 | 7.53 | 92 |
| 1993 | 7.57 | 95 |
| 1992 | 7.61 | 96 |
| 1991 | 7.62 | 101 |
| 1990 | 7.61 | 103 |
| 1989 | 7.65 | 104 |
| 1988 | 7.66 | 106 |
| 1987 | 7.66 | 106 |
| 1986 | 7.64 | 106 |