| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 46.7 | 153 |
| 2014 | 48.3 | 153 |
| 2013 | 47.3 | 156 |
| 2012 | 40.9 | 158 |
| 2011 | 39.9 | 160 |
| 2010 | 33.3 | 159 |
| 2009 | 31.6 | 157 |
| 2008 | 41 | 152 |
| 2007 | 38.3 | 152 |
| 2006 | 36.6 | 147 |
| 2005 | 33.7 | 146 |
| 2004 | 31.8 | 146 |
| 2003 | 25.1 | 146 |
| 2002 | 18.9 | 149 |
| 2001 | 17.9 | 145 |
| 2000 | 17.7 | 144 |
| 1999 | 19.5 | 140 |
| 1998 | 16.2 | 146 |
| 1997 | 20.4 | 141 |
| 1996 | 20.4 | 142 |
| 1995 | 19.6 | 139 |
| 1994 | 18.8 | 130 |
| 1993 | 17.5 | 130 |
| 1992 | 15.8 | 131 |
| 1991 | 14.3 | 134 |
| 1990 | 14 | 130 |
| 1989 | 11.6 | 115 |
| 1988 | 10.8 | 113 |
| 1987 | 11.4 | 113 |
| 1986 | 12.6 | 109 |