| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 65.8 | 82 |
| 2015 | 66.2 | 77 |
| 2014 | 66.5 | 73 |
| 2013 | 66.8 | 70 |
| 2012 | 67 | 68 |
| 2011 | 67.3 | 67 |
| 2010 | 67.5 | 62 |
| 2009 | 67.6 | 58 |
| 2008 | 67.6 | 57 |
| 2007 | 67.6 | 53 |
| 2006 | 67.5 | 51 |
| 2005 | 67.3 | 49 |
| 2004 | 67.2 | 48 |
| 2003 | 67.1 | 47 |
| 2002 | 67 | 48 |
| 2001 | 66.9 | 48 |
| 2000 | 66.8 | 51 |
| 1999 | 66.7 | 49 |
| 1998 | 66.7 | 46 |
| 1997 | 66.6 | 42 |
| 1996 | 66.5 | 41 |
| 1995 | 66.6 | 38 |
| 1994 | 66.6 | 37 |
| 1993 | 66.7 | 33 |
| 1992 | 66.8 | 27 |
| 1991 | 66.9 | 27 |
| 1990 | 66.8 | 25 |
| 1989 | 66.8 | 27 |
| 1988 | 66.6 | 31 |
| 1987 | 66.4 | 31 |
| 1986 | 66.2 | 34 |