| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 53.6 | 176 |
| 2015 | 53 | 177 |
| 2014 | 52.3 | 180 |
| 2013 | 51.5 | 184 |
| 2012 | 50.9 | 186 |
| 2011 | 50.3 | 189 |
| 2010 | 49.9 | 189 |
| 2009 | 49.8 | 189 |
| 2008 | 49.8 | 189 |
| 2007 | 49.9 | 189 |
| 2006 | 50.1 | 188 |
| 2005 | 50.2 | 188 |
| 2004 | 50 | 189 |
| 2003 | 49.7 | 189 |
| 2002 | 49.5 | 189 |
| 2001 | 49.3 | 188 |
| 2000 | 49.2 | 189 |
| 1999 | 49.3 | 189 |
| 1998 | 49.4 | 190 |
| 1997 | 49.5 | 188 |
| 1996 | 49.7 | 187 |
| 1995 | 49.9 | 183 |
| 1994 | 49.8 | 182 |
| 1993 | 49.8 | 180 |
| 1992 | 49.8 | 180 |
| 1991 | 49.8 | 179 |
| 1990 | 49.7 | 178 |
| 1989 | 50.1 | 175 |
| 1988 | 50.2 | 172 |
| 1987 | 50.2 | 173 |
| 1986 | 50.3 | 170 |