| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 50.7 | 187 |
| 2015 | 50.6 | 187 |
| 2014 | 50.4 | 189 |
| 2013 | 50.2 | 189 |
| 2012 | 50 | 189 |
| 2011 | 49.8 | 190 |
| 2010 | 49.7 | 191 |
| 2009 | 49.5 | 191 |
| 2008 | 49.4 | 191 |
| 2007 | 49.4 | 191 |
| 2006 | 49.5 | 190 |
| 2005 | 49.5 | 190 |
| 2004 | 49.5 | 190 |
| 2003 | 49.5 | 190 |
| 2002 | 49.6 | 188 |
| 2001 | 49.8 | 187 |
| 2000 | 50.2 | 184 |
| 1999 | 50.4 | 180 |
| 1998 | 50.8 | 180 |
| 1997 | 51.1 | 175 |
| 1996 | 51.5 | 167 |
| 1995 | 51.9 | 162 |
| 1994 | 52.2 | 157 |
| 1993 | 52.3 | 150 |
| 1992 | 52.4 | 145 |
| 1991 | 52.6 | 139 |
| 1990 | 52.9 | 134 |
| 1989 | 52.9 | 131 |
| 1988 | 53 | 131 |
| 1987 | 53.1 | 132 |
| 1986 | 53.2 | 131 |