| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 65.4 | 91 |
| 2015 | 65.9 | 83 |
| 2014 | 66.5 | 76 |
| 2013 | 67 | 67 |
| 2012 | 67.6 | 59 |
| 2011 | 68.2 | 50 |
| 2010 | 68.6 | 42 |
| 2009 | 68.9 | 41 |
| 2008 | 69 | 33 |
| 2007 | 69.1 | 30 |
| 2006 | 69.1 | 30 |
| 2005 | 69.1 | 26 |
| 2004 | 68.8 | 26 |
| 2003 | 68.5 | 27 |
| 2002 | 68.2 | 29 |
| 2001 | 68 | 30 |
| 2000 | 67.7 | 35 |
| 1999 | 67.5 | 36 |
| 1998 | 67.3 | 35 |
| 1997 | 67.2 | 33 |
| 1996 | 67.1 | 32 |
| 1995 | 67 | 33 |
| 1994 | 66.8 | 32 |
| 1993 | 66.6 | 34 |
| 1992 | 66.5 | 33 |
| 1991 | 66.4 | 34 |
| 1990 | 66.5 | 34 |
| 1989 | 66.5 | 32 |
| 1988 | 66.7 | 30 |
| 1987 | 66.9 | 24 |
| 1986 | 67 | 22 |