| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 23.1 | 174 |
| 2015 | 22.3 | 174 |
| 2014 | 21.6 | 171 |
| 2013 | 20.9 | 173 |
| 2012 | 20.1 | 174 |
| 2011 | 19.4 | 176 |
| 2010 | 18.7 | 178 |
| 2009 | 18.1 | 179 |
| 2008 | 17.5 | 180 |
| 2007 | 16.8 | 180 |
| 2006 | 16.3 | 180 |
| 2005 | 15.7 | 181 |
| 2004 | 15.1 | 181 |
| 2003 | 14.6 | 181 |
| 2002 | 14.1 | 181 |
| 2001 | 13.6 | 182 |
| 2000 | 13.2 | 183 |
| 1999 | 12.8 | 182 |
| 1998 | 12.4 | 182 |
| 1997 | 12.1 | 181 |
| 1996 | 11.8 | 182 |
| 1995 | 11.4 | 182 |
| 1994 | 11.1 | 181 |
| 1993 | 10.8 | 181 |
| 1992 | 10.4 | 180 |
| 1991 | 10.1 | 181 |
| 1990 | 9.8 | 178 |
| 1989 | 9.5 | 176 |
| 1988 | 9.2 | 176 |
| 1987 | 9 | 176 |
| 1986 | 8.8 | 177 |