| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 13 | 68 |
| 2015 | 12 | 111 |
| 2014 | 11 | 118 |
| 2013 | 10 | 120 |
| 2012 | 10 | 119 |
| 2011 | 9 | 117 |
| 2010 | 7 | 118 |
| 2009 | 7 | 119 |
| 2008 | 7 | 118 |
| 2007 | 5 | 124 |
| 2006 | 4 | 120 |
| 2005 | 5 | 108 |
| 2004 | 4 | 107 |
| 2003 | 4 | 107 |
| 2002 | 3 | 108 |
| 2001 | 3 | 103 |
| 2000 | 3 | 108 |
| 1999 | 3 | 106 |
| 1998 | 2 | 107 |
| 1997 | 2 | 106 |
| 1996 | 1 | 104 |
| 1995 | 1 | 105 |
| 1994 | 1 | 106 |
| 1993 | 1 | 109 |
| 1992 | 1 | 110 |
| 1991 | 1 | 107 |
| 1990 | 0 | 112 |
| 1989 | 0 | 120 |
| 1988 | 0 | 105 |
| 1987 | 0 | 108 |
| 1986 | 0 | 103 |