| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 41.4 | 31 |
| 2015 | 41.5 | 34 |
| 2014 | 41.5 | 35 |
| 2013 | 41.5 | 35 |
| 2012 | 41.5 | 37 |
| 2011 | 41.5 | 40 |
| 2010 | 41.5 | 40 |
| 2009 | 41.5 | 39 |
| 2008 | 41.5 | 40 |
| 2007 | 41.6 | 40 |
| 2006 | 41.7 | 40 |
| 2005 | 41.8 | 41 |
| 2004 | 42 | 42 |
| 2003 | 42.1 | 43 |
| 2002 | 42.3 | 43 |
| 2001 | 42.5 | 43 |
| 2000 | 42.8 | 44 |
| 1999 | 43.2 | 44 |
| 1998 | 43.6 | 42 |
| 1997 | 44 | 41 |
| 1996 | 44.4 | 37 |
| 1995 | 44.7 | 35 |
| 1994 | 45.2 | 32 |
| 1993 | 45.6 | 30 |
| 1992 | 45.9 | 30 |
| 1991 | 46.1 | 25 |
| 1990 | 46.3 | 20 |
| 1989 | 46.8 | 18 |
| 1988 | 47.3 | 14 |
| 1987 | 47.6 | 9 |
| 1986 | 47.9 | 8 |