| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 11 | 115 |
| 2014 | 18 | 105 |
| 2013 | 23 | 97 |
| 2012 | 24 | 94 |
| 2011 | 23 | 99 |
| 2010 | 19 | 99 |
| 2009 | 18 | 98 |
| 2008 | 21 | 95 |
| 2007 | 17 | 96 |
| 2006 | 17 | 91 |
| 2005 | 12 | 94 |
| 2004 | 10 | 101 |
| 2003 | 8 | 108 |
| 2002 | 6 | 110 |
| 2001 | 6 | 104 |
| 2000 | 6 | 110 |
| 1999 | 6 | 107 |
| 1998 | 6 | 115 |
| 1997 | 6 | 112 |
| 1996 | 5 | 116 |
| 1995 | 5 | 106 |
| 1994 | 4 | 98 |
| 1993 | 10 | 75 |
| 1992 | 7 | 80 |
| 1991 | 5 | 95 |
| 1990 | 6 | 89 |
| 1989 | 8 | 65 |
| 1988 | 6 | 70 |
| 1987 | 2 | 89 |
| 1986 | 2 | 85 |