| 时间 | 值 （万人） | 世界排名 |
|---|---|---|
| 2016 | 21.8 | 169 |
| 2015 | 21.3 | 169 |
| 2014 | 20.7 | 169 |
| 2013 | 20.1 | 169 |
| 2012 | 19.4 | 170 |
| 2011 | 18.8 | 171 |
| 2010 | 18 | 172 |
| 2009 | 17.3 | 172 |
| 2008 | 17 | 172 |
| 2007 | 16 | 173 |
| 2006 | 14.9 | 174 |
| 2005 | 13.7 | 174 |
| 2004 | 12.6 | 174 |
| 2003 | 11.6 | 174 |
| 2002 | 10.7 | 174 |
| 2001 | 10 | 174 |
| 2000 | 9.2 | 175 |
| 1999 | 8.7 | 176 |
| 1998 | 8.1 | 177 |
| 1997 | 7.6 | 178 |
| 1996 | 7.3 | 177 |
| 1995 | 6.9 | 179 |
| 1994 | 6.6 | 178 |
| 1993 | 6.4 | 178 |
| 1992 | 6.1 | 179 |
| 1991 | 5.9 | 181 |
| 1990 | 5.7 | 182 |