| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 46.5 | 6 |
| 2015 | 46.7 | 6 |
| 2014 | 46.9 | 6 |
| 2013 | 47.1 | 6 |
| 2012 | 47.4 | 5 |
| 2011 | 47.6 | 5 |
| 2010 | 47.7 | 5 |
| 2009 | 47.8 | 5 |
| 2008 | 47.9 | 4 |
| 2007 | 47.9 | 4 |
| 2006 | 47.9 | 5 |
| 2005 | 47.9 | 5 |
| 2004 | 47.8 | 6 |
| 2003 | 47.8 | 6 |
| 2002 | 47.7 | 7 |
| 2001 | 47.5 | 8 |
| 2000 | 47.1 | 10 |
| 1999 | 46.9 | 10 |
| 1998 | 46.5 | 15 |
| 1997 | 46.1 | 17 |
| 1996 | 45.7 | 22 |
| 1995 | 45.3 | 30 |
| 1994 | 45 | 34 |
| 1993 | 44.8 | 39 |
| 1992 | 44.6 | 47 |
| 1991 | 44.4 | 49 |
| 1990 | 44.1 | 53 |
| 1989 | 44.1 | 56 |
| 1988 | 44 | 59 |
| 1987 | 43.8 | 60 |
| 1986 | 43.7 | 61 |