| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2013 | 6 | 142 |
| 2012 | 8 | 136 |
| 2011 | 5 | 144 |
| 2010 | 4 | 146 |
| 2009 | 3 | 147 |
| 2008 | 4 | 142 |
| 2007 | 3 | 150 |
| 2006 | 2 | 147 |
| 2005 | 2 | 145 |
| 2004 | 2 | 134 |
| 2003 | 2 | 131 |
| 2002 | 2 | 132 |
| 2001 | 2 | 118 |
| 2000 | 2 | 124 |
| 1999 | 3 | 110 |
| 1998 | 3 | 106 |
| 1997 | 2 | 113 |
| 1996 | 3 | 101 |
| 1995 | 3 | 100 |
| 1994 | 2 | 98 |
| 1993 | 2 | 94 |
| 1992 | 2 | 93 |
| 1991 | 3 | 88 |
| 1990 | 2 | 86 |
| 1989 | 2 | 94 |
| 1988 | 2 | 94 |
| 1987 | 1 | 102 |
| 1986 | 1 | 99 |