| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2013 | 74 | 63 |
| 2012 | 63 | 65 |
| 2011 | 36 | 76 |
| 2010 | 53 | 63 |
| 2009 | 43 | 67 |
| 2008 | 36 | 72 |
| 2007 | 25 | 80 |
| 2006 | 23 | 75 |
| 2005 | 21 | 72 |
| 2004 | 18 | 70 |
| 2003 | 15 | 69 |
| 2002 | 13 | 67 |
| 2001 | 10 | 72 |
| 2000 | 8 | 77 |
| 1999 | 9 | 71 |
| 1998 | 7 | 87 |
| 1997 | 7 | 79 |
| 1996 | 7 | 76 |
| 1995 | 5 | 81 |
| 1994 | 6 | 71 |
| 1993 | 8 | 61 |
| 1992 | 8 | 57 |
| 1991 | 22 | 37 |
| 1990 | 9 | 49 |
| 1989 | 10 | 45 |
| 1988 | 10 | 44 |
| 1987 | 10 | 42 |
| 1986 | 9 | 43 |