| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 44.9 | 13 |
| 2015 | 44.8 | 13 |
| 2014 | 44.6 | 15 |
| 2013 | 44.5 | 16 |
| 2012 | 44.4 | 16 |
| 2011 | 44.2 | 16 |
| 2010 | 44.1 | 18 |
| 2009 | 44.3 | 17 |
| 2008 | 44.6 | 17 |
| 2007 | 44.9 | 17 |
| 2006 | 45.3 | 17 |
| 2005 | 45.7 | 15 |
| 2004 | 46.3 | 13 |
| 2003 | 47 | 8 |
| 2002 | 47.8 | 6 |
| 2001 | 48.6 | 4 |
| 2000 | 49.3 | 3 |
| 1999 | 49.5 | 2 |
| 1998 | 49.6 | 1 |
| 1997 | 49.6 | 2 |
| 1996 | 49.6 | 2 |
| 1995 | 49.5 | 2 |
| 1994 | 49.3 | 2 |
| 1993 | 49.1 | 2 |
| 1992 | 48.7 | 2 |
| 1991 | 48.2 | 8 |
| 1990 | 47.4 | 13 |
| 1989 | 47.3 | 13 |
| 1988 | 47 | 17 |
| 1987 | 46.6 | 22 |
| 1986 | 46.1 | 31 |