| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 55.4 | 164 |
| 2015 | 55.2 | 163 |
| 2014 | 55 | 163 |
| 2013 | 54.9 | 162 |
| 2012 | 54.8 | 162 |
| 2011 | 54.8 | 161 |
| 2010 | 54.8 | 163 |
| 2009 | 54.7 | 160 |
| 2008 | 54.7 | 160 |
| 2007 | 54.6 | 159 |
| 2006 | 54.6 | 159 |
| 2005 | 54.6 | 158 |
| 2004 | 54.5 | 156 |
| 2003 | 54.3 | 154 |
| 2002 | 54.1 | 151 |
| 2001 | 53.9 | 150 |
| 2000 | 53.8 | 151 |
| 1999 | 53.3 | 154 |
| 1998 | 52.9 | 156 |
| 1997 | 52.4 | 157 |
| 1996 | 52 | 163 |
| 1995 | 51.5 | 167 |
| 1994 | 51.3 | 167 |
| 1993 | 51.1 | 168 |
| 1992 | 50.9 | 171 |
| 1991 | 50.8 | 168 |
| 1990 | 50.8 | 166 |
| 1989 | 50.6 | 167 |
| 1988 | 50.5 | 167 |
| 1987 | 50.4 | 166 |
| 1986 | 50.4 | 168 |