| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 28 | 86 |
| 2014 | 30 | 85 |
| 2013 | 23 | 96 |
| 2012 | 19 | 104 |
| 2011 | 16 | 106 |
| 2010 | 11 | 108 |
| 2009 | 10 | 107 |
| 2008 | 10 | 112 |
| 2007 | 9 | 111 |
| 2006 | 8 | 106 |
| 2005 | 7 | 109 |
| 2004 | 6 | 102 |
| 2003 | 5 | 101 |
| 2002 | 4 | 105 |
| 2001 | 4 | 102 |
| 2000 | 5 | 98 |
| 1999 | 4 | 95 |
| 1998 | 4 | 97 |
| 1997 | 4 | 93 |
| 1996 | 3 | 96 |
| 1995 | 3 | 96 |
| 1994 | 3 | 89 |
| 1993 | 3 | 86 |
| 1992 | 3 | 85 |
| 1991 | 3 | 84 |
| 1990 | 3 | 83 |
| 1989 | 3 | 79 |
| 1988 | 2 | 82 |
| 1987 | 2 | 76 |
| 1986 | 2 | 76 |