| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 10.43 | 58 |
| 2015 | 10.11 | 74 |
| 2014 | 9.48 | 78 |
| 2013 | 9.21 | 84 |
| 2012 | 9.06 | 82 |
| 2011 | 9.94 | 77 |
| 2010 | 10.18 | 77 |
| 2009 | 10.5 | 72 |
| 2008 | 9.3 | 85 |
| 2007 | 9.84 | 81 |
| 2006 | 9.9 | 85 |
| 2005 | 10.04 | 85 |
| 2004 | 10.37 | 84 |
| 2003 | 11.66 | 79 |
| 2002 | 12.22 | 77 |
| 2001 | 13.74 | 73 |
| 2000 | 16.34 | 63 |
| 1999 | 18.33 | 60 |
| 1998 | 18.32 | 60 |
| 1997 | 20.91 | 54 |
| 1996 | 21.39 | 52 |
| 1995 | 22.62 | 49 |
| 1994 | 22.97 | 51 |
| 1993 | 24.31 | 46 |
| 1992 | 19.68 | 56 |
| 1991 | 21.73 | 51 |
| 1990 | 21.43 | 54 |
| 1989 | 23.4 | 45 |
| 1988 | 23.04 | 45 |
| 1987 | 22.36 | 48 |
| 1986 | 21.85 | 45 |