| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2014 | 27 | 89 |
| 2013 | 22 | 98 |
| 2012 | 23 | 95 |
| 2011 | 20 | 96 |
| 2010 | 19 | 94 |
| 2009 | 17 | 96 |
| 2008 | 17 | 97 |
| 2007 | 15 | 98 |
| 2006 | 13 | 96 |
| 2005 | 10 | 101 |
| 2004 | 8 | 96 |
| 2003 | 6 | 99 |
| 2002 | 6 | 93 |
| 2001 | 7 | 83 |
| 2000 | 7 | 85 |
| 1999 | 13 | 63 |
| 1998 | 12 | 62 |
| 1997 | 11 | 67 |
| 1996 | 8 | 74 |
| 1995 | 9 | 65 |
| 1994 | 10 | 57 |
| 1993 | 9 | 58 |
| 1992 | 5 | 72 |
| 1991 | 5 | 64 |
| 1990 | 6 | 61 |
| 1989 | 5 | 61 |
| 1988 | 4 | 65 |
| 1987 | 4 | 65 |
| 1986 | 3 | 64 |