| 时间 | 值 （万人） | 世界排名 |
|---|---|---|
| 2016 | 32.5 | 160 |
| 2015 | 32.1 | 160 |
| 2014 | 31.7 | 160 |
| 2013 | 31.3 | 159 |
| 2012 | 30.9 | 159 |
| 2011 | 30.5 | 160 |
| 2010 | 30.2 | 160 |
| 2009 | 29.9 | 160 |
| 2008 | 29.6 | 160 |
| 2007 | 29.3 | 160 |
| 2006 | 29.1 | 159 |
| 2005 | 28.8 | 159 |
| 2004 | 28.8 | 159 |
| 2003 | 28.8 | 158 |
| 2002 | 28.8 | 158 |
| 2001 | 28.9 | 158 |
| 2000 | 28.9 | 157 |
| 1999 | 29 | 156 |
| 1998 | 29.1 | 155 |
| 1997 | 29.1 | 156 |
| 1996 | 29.1 | 156 |
| 1995 | 29 | 156 |
| 1994 | 29 | 154 |
| 1993 | 29 | 153 |
| 1992 | 28.8 | 153 |
| 1991 | 28.5 | 154 |
| 1990 | 28.3 | 154 |