| 时间 | 值 （万人） | 世界排名 |
|---|---|---|
| 2016 | 15.9 | 165 |
| 2015 | 15.4 | 167 |
| 2014 | 15.1 | 167 |
| 2013 | 14.9 | 167 |
| 2012 | 14.8 | 167 |
| 2011 | 14.6 | 168 |
| 2010 | 14.2 | 168 |
| 2009 | 13.6 | 169 |
| 2008 | 12.9 | 169 |
| 2007 | 12 | 169 |
| 2006 | 11.1 | 170 |
| 2005 | 10.3 | 171 |
| 2004 | 9.6 | 172 |
| 2003 | 9.1 | 172 |
| 2002 | 8.5 | 172 |
| 2001 | 8.1 | 174 |
| 2000 | 7.7 | 174 |
| 1999 | 7.4 | 175 |
| 1998 | 7.1 | 176 |
| 1997 | 6.9 | 176 |
| 1996 | 6.7 | 176 |
| 1995 | 6.5 | 177 |
| 1994 | 6.4 | 178 |
| 1993 | 6.2 | 178 |
| 1992 | 6.1 | 179 |
| 1991 | 5.9 | 179 |
| 1990 | 5.9 | 179 |
| 1989 | 5.8 | 177 |
| 1988 | 5.7 | 178 |
| 1987 | 5.6 | 178 |
| 1986 | 5.5 | 178 |