| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 9.67 | 96 |
| 2015 | 9.43 | 96 |
| 2014 | 9.22 | 96 |
| 2013 | 9.03 | 95 |
| 2012 | 8.88 | 96 |
| 2011 | 8.74 | 98 |
| 2010 | 8.61 | 97 |
| 2009 | 8.49 | 95 |
| 2008 | 8.37 | 95 |
| 2007 | 8.27 | 96 |
| 2006 | 8.17 | 94 |
| 2005 | 8.07 | 93 |
| 2004 | 8 | 92 |
| 2003 | 7.92 | 91 |
| 2002 | 7.85 | 91 |
| 2001 | 7.79 | 91 |
| 2000 | 7.74 | 91 |
| 1999 | 7.74 | 92 |
| 1998 | 7.76 | 93 |
| 1997 | 7.8 | 94 |
| 1996 | 7.82 | 97 |
| 1995 | 7.81 | 99 |
| 1994 | 7.8 | 99 |
| 1993 | 7.75 | 101 |
| 1992 | 7.67 | 100 |
| 1991 | 7.58 | 97 |
| 1990 | 7.49 | 97 |
| 1989 | 7.43 | 94 |
| 1988 | 7.38 | 94 |
| 1987 | 7.34 | 93 |
| 1986 | 7.29 | 94 |