| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 62.7 | 127 |
| 2015 | 62 | 129 |
| 2014 | 61.3 | 133 |
| 2013 | 60.5 | 136 |
| 2012 | 59.6 | 138 |
| 2011 | 58.8 | 140 |
| 2010 | 58.1 | 144 |
| 2009 | 57.6 | 145 |
| 2008 | 57.2 | 145 |
| 2007 | 56.9 | 145 |
| 2006 | 56.5 | 145 |
| 2005 | 56 | 145 |
| 2004 | 55.9 | 142 |
| 2003 | 55.7 | 142 |
| 2002 | 55.5 | 141 |
| 2001 | 55.4 | 140 |
| 2000 | 55.2 | 138 |
| 1999 | 55.1 | 134 |
| 1998 | 55 | 132 |
| 1997 | 54.9 | 130 |
| 1996 | 54.8 | 128 |
| 1995 | 54.8 | 128 |
| 1994 | 54.6 | 128 |
| 1993 | 54.3 | 128 |
| 1992 | 54.2 | 126 |
| 1991 | 54.1 | 124 |
| 1990 | 54 | 124 |
| 1989 | 54.1 | 123 |
| 1988 | 54.1 | 121 |
| 1987 | 54.3 | 120 |
| 1986 | 54.4 | 117 |