| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 64.1 | 114 |
| 2015 | 64.6 | 106 |
| 2014 | 65 | 104 |
| 2013 | 65.2 | 101 |
| 2012 | 65.4 | 98 |
| 2011 | 65.6 | 95 |
| 2010 | 65.6 | 94 |
| 2009 | 65.4 | 97 |
| 2008 | 65 | 98 |
| 2007 | 64.6 | 97 |
| 2006 | 64 | 100 |
| 2005 | 63.4 | 102 |
| 2004 | 62.5 | 105 |
| 2003 | 61.6 | 108 |
| 2002 | 60.8 | 110 |
| 2001 | 60.1 | 111 |
| 2000 | 59.6 | 112 |
| 1999 | 58.9 | 112 |
| 1998 | 58.3 | 111 |
| 1997 | 57.8 | 111 |
| 1996 | 57.3 | 113 |
| 1995 | 57 | 112 |
| 1994 | 56.9 | 112 |
| 1993 | 56.9 | 110 |
| 1992 | 57 | 107 |
| 1991 | 57.2 | 104 |
| 1990 | 57.5 | 99 |
| 1989 | 57.7 | 94 |
| 1988 | 57.8 | 94 |
| 1987 | 57.9 | 93 |
| 1986 | 58.1 | 87 |