| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 31 | 82 |
| 2014 | 33 | 82 |
| 2013 | 34 | 77 |
| 2012 | 36 | 76 |
| 2011 | 36 | 71 |
| 2010 | 27 | 77 |
| 2009 | 23 | 78 |
| 2008 | 22 | 80 |
| 2007 | 18 | 83 |
| 2006 | 14 | 89 |
| 2005 | 13 | 84 |
| 2004 | 11 | 82 |
| 2003 | 7 | 86 |
| 2002 | 7 | 86 |
| 2001 | 11 | 74 |
| 2000 | 12 | 66 |
| 1999 | 12 | 64 |
| 1998 | 13 | 62 |
| 1997 | 14 | 58 |
| 1996 | 14 | 57 |
| 1995 | 13 | 55 |
| 1994 | 13 | 53 |
| 1993 | 10 | 56 |
| 1992 | 8 | 53 |
| 1991 | 6 | 56 |
| 1990 | 5 | 60 |
| 1989 | 4 | 61 |
| 1988 | 3 | 62 |
| 1987 | 4 | 57 |
| 1986 | 4 | 57 |