| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 22.2 | 178 |
| 2015 | 21.7 | 177 |
| 2014 | 21.2 | 174 |
| 2013 | 20.8 | 174 |
| 2012 | 20.3 | 173 |
| 2011 | 19.8 | 173 |
| 2010 | 19.4 | 173 |
| 2009 | 18.9 | 173 |
| 2008 | 18.5 | 173 |
| 2007 | 18 | 173 |
| 2006 | 17.6 | 174 |
| 2005 | 17.2 | 175 |
| 2004 | 16.7 | 175 |
| 2003 | 16.3 | 174 |
| 2002 | 15.9 | 174 |
| 2001 | 15.5 | 174 |
| 2000 | 15.2 | 174 |
| 1999 | 14.9 | 172 |
| 1998 | 14.6 | 172 |
| 1997 | 14.4 | 172 |
| 1996 | 14.1 | 172 |
| 1995 | 13.8 | 172 |
| 1994 | 13.5 | 171 |
| 1993 | 13.1 | 171 |
| 1992 | 12.7 | 170 |
| 1991 | 12.4 | 171 |
| 1990 | 12 | 168 |
| 1989 | 11.7 | 166 |
| 1988 | 11.4 | 167 |
| 1987 | 11.2 | 168 |
| 1986 | 10.9 | 168 |