| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 51.1 | 143 |
| 2015 | 50.5 | 143 |
| 2014 | 50 | 139 |
| 2013 | 49.4 | 138 |
| 2012 | 48.8 | 138 |
| 2011 | 48.3 | 139 |
| 2010 | 47.7 | 139 |
| 2009 | 47.1 | 139 |
| 2008 | 46.5 | 140 |
| 2007 | 45.9 | 140 |
| 2006 | 45.3 | 141 |
| 2005 | 44.7 | 141 |
| 2004 | 44.1 | 140 |
| 2003 | 43.6 | 140 |
| 2002 | 43 | 139 |
| 2001 | 42.4 | 139 |
| 2000 | 41.8 | 139 |
| 1999 | 41.1 | 137 |
| 1998 | 40.5 | 136 |
| 1997 | 39.8 | 135 |
| 1996 | 39.1 | 136 |
| 1995 | 38.3 | 136 |
| 1994 | 37.6 | 135 |
| 1993 | 36.8 | 135 |
| 1992 | 36 | 136 |
| 1991 | 35.2 | 138 |
| 1990 | 34.4 | 136 |
| 1989 | 33.7 | 134 |
| 1988 | 33 | 134 |
| 1987 | 32.3 | 134 |
| 1986 | 31.6 | 134 |