| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 24.1 | 173 |
| 2015 | 23.9 | 173 |
| 2014 | 23.7 | 170 |
| 2013 | 23.5 | 170 |
| 2012 | 23.3 | 170 |
| 2011 | 23.1 | 170 |
| 2010 | 22.9 | 170 |
| 2009 | 22.6 | 171 |
| 2008 | 22.4 | 170 |
| 2007 | 22.2 | 170 |
| 2006 | 21.9 | 170 |
| 2005 | 21.7 | 170 |
| 2004 | 21.5 | 170 |
| 2003 | 21.2 | 170 |
| 2002 | 21 | 170 |
| 2001 | 20.8 | 170 |
| 2000 | 20.5 | 169 |
| 1999 | 20.3 | 166 |
| 1998 | 20 | 166 |
| 1997 | 19.8 | 164 |
| 1996 | 19.5 | 164 |
| 1995 | 19.2 | 164 |
| 1994 | 19 | 163 |
| 1993 | 18.7 | 162 |
| 1992 | 18.4 | 161 |
| 1991 | 18.1 | 162 |
| 1990 | 17.8 | 159 |
| 1989 | 17.5 | 158 |
| 1988 | 17.2 | 158 |
| 1987 | 16.9 | 156 |
| 1986 | 16.7 | 156 |