| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 31.7 | 166 |
| 2015 | 31.1 | 167 |
| 2014 | 30.4 | 165 |
| 2013 | 29.8 | 165 |
| 2012 | 29.2 | 165 |
| 2011 | 28.8 | 166 |
| 2010 | 28.4 | 166 |
| 2009 | 28.1 | 165 |
| 2008 | 27.7 | 165 |
| 2007 | 27.5 | 165 |
| 2006 | 27.2 | 165 |
| 2005 | 26.9 | 164 |
| 2004 | 26.6 | 162 |
| 2003 | 26.3 | 162 |
| 2002 | 26 | 162 |
| 2001 | 25.8 | 162 |
| 2000 | 25.5 | 162 |
| 1999 | 25.2 | 160 |
| 1998 | 24.9 | 160 |
| 1997 | 24.5 | 158 |
| 1996 | 24.1 | 157 |
| 1995 | 23.8 | 157 |
| 1994 | 23.5 | 156 |
| 1993 | 23.5 | 155 |
| 1992 | 23.5 | 154 |
| 1991 | 23.3 | 154 |
| 1990 | 22.9 | 149 |
| 1989 | 22.5 | 147 |
| 1988 | 22 | 148 |
| 1987 | 21.6 | 147 |
| 1986 | 21.2 | 147 |