| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 54.8 | 167 |
| 2015 | 54.6 | 167 |
| 2014 | 54.3 | 167 |
| 2013 | 54 | 167 |
| 2012 | 53.8 | 167 |
| 2011 | 53.7 | 169 |
| 2010 | 53.6 | 170 |
| 2009 | 53.5 | 168 |
| 2008 | 53.5 | 168 |
| 2007 | 53.5 | 164 |
| 2006 | 53.6 | 164 |
| 2005 | 53.7 | 161 |
| 2004 | 53.7 | 161 |
| 2003 | 53.6 | 161 |
| 2002 | 53.6 | 158 |
| 2001 | 53.6 | 155 |
| 2000 | 53.7 | 153 |
| 1999 | 53.5 | 151 |
| 1998 | 53.3 | 148 |
| 1997 | 53.3 | 148 |
| 1996 | 53.1 | 148 |
| 1995 | 52.9 | 145 |
| 1994 | 52.9 | 144 |
| 1993 | 52.6 | 144 |
| 1992 | 52.3 | 148 |
| 1991 | 52.1 | 151 |
| 1990 | 52 | 153 |
| 1989 | 51.8 | 153 |
| 1988 | 51.6 | 152 |
| 1987 | 51.6 | 150 |
| 1986 | 51.7 | 148 |