| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 65 | 100 |
| 2015 | 65.2 | 100 |
| 2014 | 65.4 | 98 |
| 2013 | 65.7 | 95 |
| 2012 | 65.9 | 88 |
| 2011 | 66.1 | 86 |
| 2010 | 66.4 | 83 |
| 2009 | 66.5 | 79 |
| 2008 | 66.7 | 74 |
| 2007 | 66.8 | 69 |
| 2006 | 67 | 58 |
| 2005 | 67.3 | 48 |
| 2004 | 67.4 | 44 |
| 2003 | 67.5 | 42 |
| 2002 | 67.6 | 42 |
| 2001 | 67.6 | 39 |
| 2000 | 67.7 | 36 |
| 1999 | 67.6 | 32 |
| 1998 | 67.6 | 30 |
| 1997 | 67.4 | 28 |
| 1996 | 67.3 | 29 |
| 1995 | 67.2 | 30 |
| 1994 | 67 | 30 |
| 1993 | 66.7 | 30 |
| 1992 | 66.5 | 32 |
| 1991 | 66.2 | 38 |
| 1990 | 65.8 | 46 |
| 1989 | 65.5 | 47 |
| 1988 | 65.1 | 50 |
| 1987 | 64.8 | 52 |
| 1986 | 64.5 | 53 |