| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 26 | 89 |
| 2014 | 31 | 81 |
| 2013 | 32 | 83 |
| 2012 | 24 | 92 |
| 2011 | 20 | 97 |
| 2010 | 15 | 100 |
| 2009 | 12 | 100 |
| 2008 | 15 | 99 |
| 2007 | 11 | 106 |
| 2006 | 9 | 103 |
| 2005 | 9 | 104 |
| 2004 | 7 | 97 |
| 2003 | 6 | 97 |
| 2002 | 6 | 94 |
| 2001 | 8 | 80 |
| 2000 | 8 | 75 |
| 1999 | 8 | 78 |
| 1998 | 8 | 74 |
| 1997 | 8 | 74 |
| 1996 | 8 | 73 |
| 1995 | 8 | 68 |
| 1994 | 8 | 67 |
| 1993 | 7 | 69 |
| 1992 | 5 | 70 |
| 1991 | 4 | 74 |
| 1990 | 4 | 77 |
| 1989 | 4 | 72 |
| 1988 | 3 | 76 |
| 1987 | 3 | 70 |
| 1986 | 4 | 62 |