| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 53.2 | 177 |
| 2015 | 53.1 | 176 |
| 2014 | 53.1 | 176 |
| 2013 | 53 | 175 |
| 2012 | 53.1 | 177 |
| 2011 | 53.1 | 176 |
| 2010 | 53.2 | 176 |
| 2009 | 53.3 | 172 |
| 2008 | 53.3 | 169 |
| 2007 | 53.4 | 167 |
| 2006 | 53.5 | 165 |
| 2005 | 53.6 | 163 |
| 2004 | 53.6 | 162 |
| 2003 | 53.5 | 162 |
| 2002 | 53.5 | 159 |
| 2001 | 53.5 | 157 |
| 2000 | 53.6 | 155 |
| 1999 | 53.4 | 153 |
| 1998 | 53.2 | 150 |
| 1997 | 53.1 | 149 |
| 1996 | 53 | 149 |
| 1995 | 52.9 | 148 |
| 1994 | 52.6 | 148 |
| 1993 | 52.4 | 147 |
| 1992 | 52.3 | 149 |
| 1991 | 52.2 | 148 |
| 1990 | 52.1 | 151 |
| 1989 | 52 | 150 |
| 1988 | 51.9 | 149 |
| 1987 | 51.9 | 146 |
| 1986 | 51.9 | 145 |