| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 8 | 119 |
| 2014 | 8 | 127 |
| 2013 | 8 | 130 |
| 2012 | 6 | 135 |
| 2011 | 5 | 131 |
| 2010 | 5 | 127 |
| 2009 | 4 | 135 |
| 2008 | 4 | 137 |
| 2007 | 3 | 141 |
| 2006 | 2 | 141 |
| 2005 | 2 | 137 |
| 2004 | 2 | 132 |
| 2003 | 1 | 136 |
| 2002 | 2 | 125 |
| 2001 | 1 | 120 |
| 2000 | 1 | 122 |
| 1999 | 2 | 111 |
| 1998 | 3 | 102 |
| 1997 | 2 | 101 |
| 1996 | 1 | 124 |
| 1995 | 1 | 113 |
| 1994 | 1 | 110 |
| 1993 | 1 | 107 |
| 1992 | 0 | 136 |
| 1991 | 0 | 122 |
| 1990 | 0 | 125 |
| 1989 | 0 | 123 |
| 1988 | 0 | 124 |
| 1987 | 0 | 122 |
| 1986 | 0 | 122 |