| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 17 | 185 |
| 2015 | 16.7 | 185 |
| 2014 | 16.4 | 183 |
| 2013 | 16.1 | 183 |
| 2012 | 15.8 | 183 |
| 2011 | 15.5 | 184 |
| 2010 | 15.2 | 184 |
| 2009 | 14.9 | 185 |
| 2008 | 14.6 | 185 |
| 2007 | 14.4 | 185 |
| 2006 | 14.2 | 185 |
| 2005 | 14 | 184 |
| 2004 | 13.8 | 184 |
| 2003 | 13.6 | 184 |
| 2002 | 13.4 | 184 |
| 2001 | 13.3 | 184 |
| 2000 | 13.1 | 184 |
| 1999 | 12.9 | 181 |
| 1998 | 12.7 | 181 |
| 1997 | 12.5 | 179 |
| 1996 | 12.3 | 179 |
| 1995 | 12.1 | 179 |
| 1994 | 11.9 | 178 |
| 1993 | 11.7 | 177 |
| 1992 | 11.4 | 176 |
| 1991 | 11.1 | 178 |
| 1990 | 10.9 | 174 |
| 1989 | 10.6 | 172 |
| 1988 | 10.3 | 172 |
| 1987 | 10 | 172 |
| 1986 | 9.8 | 172 |