| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 65.2 | 98 |
| 2015 | 65.4 | 97 |
| 2014 | 65.6 | 94 |
| 2013 | 65.8 | 93 |
| 2012 | 66 | 87 |
| 2011 | 66.2 | 84 |
| 2010 | 66.4 | 80 |
| 2009 | 66.5 | 77 |
| 2008 | 66.5 | 76 |
| 2007 | 66.5 | 75 |
| 2006 | 66.5 | 72 |
| 2005 | 66.4 | 68 |
| 2004 | 66.2 | 68 |
| 2003 | 66 | 63 |
| 2002 | 65.9 | 62 |
| 2001 | 65.7 | 61 |
| 2000 | 65.5 | 59 |
| 1999 | 65.4 | 58 |
| 1998 | 65.3 | 58 |
| 1997 | 65.3 | 55 |
| 1996 | 65.4 | 54 |
| 1995 | 65.4 | 53 |
| 1994 | 65.5 | 52 |
| 1993 | 65.5 | 50 |
| 1992 | 65.6 | 51 |
| 1991 | 65.6 | 48 |
| 1990 | 65.6 | 49 |
| 1989 | 65.6 | 45 |
| 1988 | 65.5 | 45 |
| 1987 | 65.4 | 45 |
| 1986 | 65.2 | 44 |