| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 8 | 120 |
| 2014 | 8 | 126 |
| 2013 | 8 | 129 |
| 2012 | 7 | 130 |
| 2011 | 7 | 129 |
| 2010 | 6 | 124 |
| 2009 | 5 | 129 |
| 2008 | 4 | 132 |
| 2007 | 4 | 129 |
| 2006 | 3 | 134 |
| 2005 | 2 | 131 |
| 2004 | 2 | 125 |
| 2003 | 2 | 125 |
| 2002 | 2 | 120 |
| 2001 | 2 | 112 |
| 2000 | 2 | 113 |
| 1999 | 2 | 113 |
| 1998 | 2 | 105 |
| 1997 | 3 | 98 |
| 1996 | 3 | 95 |
| 1995 | 3 | 92 |
| 1994 | 4 | 76 |
| 1993 | 4 | 73 |
| 1992 | 3 | 71 |
| 1991 | 4 | 64 |
| 1990 | 4 | 63 |
| 1989 | 4 | 62 |
| 1988 | 3 | 65 |
| 1987 | 2 | 72 |
| 1986 | 2 | 73 |