| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 59.5 | 127 |
| 2015 | 65.5 | 147 |
| 2014 | 68.3 | 146 |
| 2013 | 70 | 148 |
| 2012 | 66.1 | 149 |
| 2011 | 55.1 | 151 |
| 2010 | 48 | 151 |
| 2009 | 42.5 | 152 |
| 2008 | 48.2 | 150 |
| 2007 | 38 | 153 |
| 2006 | 31.9 | 153 |
| 2005 | 33.2 | 147 |
| 2004 | 25.8 | 150 |
| 2003 | 19.6 | 153 |
| 2002 | 15.1 | 155 |
| 2001 | 15.2 | 149 |
| 2000 | 14.9 | 147 |
| 1999 | 15.4 | 147 |
| 1998 | 14.9 | 147 |
| 1997 | 14.1 | 149 |
| 1996 | 13.8 | 150 |
| 1995 | 13.3 | 149 |
| 1994 | 12.7 | 140 |
| 1993 | 12.2 | 139 |
| 1992 | 14.7 | 135 |
| 1991 | 15.3 | 132 |
| 1990 | 11.7 | 134 |
| 1989 | 10.5 | 116 |
| 1988 | 10.8 | 112 |
| 1987 | 10.7 | 114 |
| 1986 | 9.9 | 114 |