| 时间 | 值 （人/平方公里） | 世界排名 |
|---|---|---|
| 2016 | 65 | 136 |
| 2015 | 65 | 134 |
| 2014 | 65.2 | 130 |
| 2013 | 66.1 | 130 |
| 2012 | 66.9 | 128 |
| 2011 | 67.8 | 126 |
| 2010 | 68.7 | 122 |
| 2009 | 69.6 | 120 |
| 2008 | 70.5 | 118 |
| 2007 | 71.4 | 114 |
| 2006 | 72.4 | 112 |
| 2005 | 73.3 | 111 |
| 2004 | 74.3 | 107 |
| 2003 | 75.2 | 103 |
| 2002 | 76.2 | 103 |
| 2001 | 76.7 | 103 |
| 2000 | 77.3 | 102 |
| 1999 | 77.9 | 100 |
| 1998 | 78.5 | 100 |
| 1997 | 79.3 | 96 |
| 1996 | 80.8 | 93 |
| 1995 | 82.8 | 92 |
| 1994 | 85.1 | 90 |
| 1993 | 85.9 | 90 |
| 1992 | 85.3 | 90 |
| 1991 | 84.6 | 92 |
| 1990 | 84 | 90 |
| 1989 | 84 | 87 |
| 1988 | 83.8 | 84 |
| 1987 | 83 | 83 |
| 1986 | 82.3 | 81 |