| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 61.4 | 133 |
| 2015 | 61.8 | 130 |
| 2014 | 62 | 128 |
| 2013 | 62.3 | 127 |
| 2012 | 62.8 | 122 |
| 2011 | 63.1 | 120 |
| 2010 | 63.1 | 118 |
| 2009 | 63.1 | 116 |
| 2008 | 62.9 | 115 |
| 2007 | 62.6 | 115 |
| 2006 | 62.2 | 116 |
| 2005 | 61.8 | 115 |
| 2004 | 61.2 | 117 |
| 2003 | 60.5 | 117 |
| 2002 | 59.9 | 116 |
| 2001 | 59.2 | 117 |
| 2000 | 58.5 | 117 |
| 1999 | 57.9 | 118 |
| 1998 | 57.3 | 119 |
| 1997 | 56.7 | 118 |
| 1996 | 56.2 | 119 |
| 1995 | 55.7 | 119 |
| 1994 | 55.3 | 122 |
| 1993 | 54.9 | 123 |
| 1992 | 54.6 | 122 |
| 1991 | 54.5 | 122 |
| 1990 | 54.5 | 122 |
| 1989 | 54.4 | 120 |
| 1988 | 54.5 | 119 |
| 1987 | 54.6 | 118 |
| 1986 | 54.7 | 114 |