| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 27 | 88 |
| 2014 | 15 | 108 |
| 2013 | 19 | 97 |
| 2012 | 21 | 93 |
| 2011 | 23 | 87 |
| 2010 | 26 | 78 |
| 2009 | 18 | 88 |
| 2008 | 18 | 87 |
| 2007 | 11 | 99 |
| 2006 | 21 | 76 |
| 2005 | 14 | 81 |
| 2004 | 33 | 57 |
| 2003 | 35 | 51 |
| 2002 | 25 | 52 |
| 2001 | 17 | 60 |
| 2000 | 18 | 57 |
| 1999 | 10 | 71 |
| 1998 | 9 | 74 |
| 1997 | 8 | 75 |
| 1996 | 7 | 73 |
| 1995 | 6 | 71 |
| 1994 | 4 | 80 |
| 1993 | 12 | 52 |
| 1992 | 11 | 50 |
| 1991 | 9 | 47 |
| 1990 | 10 | 47 |
| 1989 | 6 | 56 |
| 1988 | 4 | 60 |
| 1987 | 2 | 67 |
| 1986 | 3 | 63 |