| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 25 | 87 |
| 2011 | 25 | 84 |
| 2010 | 19 | 90 |
| 2009 | 15 | 96 |
| 2008 | 16 | 91 |
| 2007 | 11 | 98 |
| 2006 | 9 | 100 |
| 2005 | 8 | 100 |
| 2004 | 8 | 91 |
| 2003 | 6 | 95 |
| 2002 | 4 | 102 |
| 2001 | 3 | 100 |
| 2000 | 4 | 96 |
| 1999 | 4 | 93 |
| 1998 | 3 | 100 |
| 1997 | 3 | 91 |
| 1996 | 3 | 89 |
| 1995 | 3 | 87 |
| 1994 | 3 | 87 |
| 1993 | 2 | 86 |
| 1992 | 2 | 79 |
| 1991 | 2 | 78 |
| 1990 | 3 | 75 |
| 1989 | 3 | 75 |
| 1988 | 2 | 71 |
| 1987 | 2 | 65 |
| 1986 | 2 | 71 |