| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.53 | 78 |
| 2015 | 7.456 | 89 |
| 2014 | 6.83 | 100 |
| 2013 | 6.594 | 107 |
| 2012 | 6.66 | 110 |
| 2011 | 6.906 | 105 |
| 2010 | 7.735 | 103 |
| 2009 | 8.248 | 104 |
| 2008 | 8.163 | 110 |
| 2007 | 8.25 | 113 |
| 2006 | 8.388 | 105 |
| 2005 | 8.665 | 100 |
| 2004 | 8.823 | 102 |
| 2003 | 9.926 | 95 |
| 2002 | 10.583 | 97 |
| 2001 | 10.972 | 97 |
| 2000 | 10.479 | 107 |
| 1999 | 10.05 | 113 |
| 1998 | 10.818 | 110 |
| 1997 | 10.631 | 104 |
| 1996 | 10.618 | 104 |
| 1995 | 11.095 | 98 |
| 1994 | 10.153 | 96 |
| 1993 | 10.06 | 94 |
| 1992 | 10.608 | 84 |
| 1991 | 11.793 | 74 |
| 1990 | 11.98 | 69 |
| 1989 | 12.923 | 61 |
| 1988 | 12.47 | 54 |
| 1987 | 12.598 | 50 |
| 1986 | 12.357 | 53 |