| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 12.87 | 53 |
| 2015 | 12.53 | 54 |
| 2014 | 12.27 | 53 |
| 2013 | 12.06 | 52 |
| 2012 | 11.91 | 52 |
| 2011 | 11.76 | 50 |
| 2010 | 11.6 | 50 |
| 2009 | 11.49 | 50 |
| 2008 | 11.38 | 51 |
| 2007 | 11.27 | 51 |
| 2006 | 11.14 | 50 |
| 2005 | 11 | 49 |
| 2004 | 10.82 | 49 |
| 2003 | 10.62 | 49 |
| 2002 | 10.39 | 50 |
| 2001 | 10.15 | 51 |
| 2000 | 9.89 | 53 |
| 1999 | 9.67 | 53 |
| 1998 | 9.44 | 53 |
| 1997 | 9.19 | 54 |
| 1996 | 8.95 | 54 |
| 1995 | 8.7 | 53 |
| 1994 | 8.38 | 54 |
| 1993 | 8.08 | 54 |
| 1992 | 7.79 | 54 |
| 1991 | 7.49 | 56 |
| 1990 | 7.2 | 58 |
| 1989 | 6.94 | 57 |
| 1988 | 6.69 | 58 |
| 1987 | 6.45 | 58 |
| 1986 | 6.26 | 57 |