| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 37 | 77 |
| 2014 | 34 | 80 |
| 2013 | 32 | 82 |
| 2012 | 28 | 82 |
| 2011 | 23 | 88 |
| 2010 | 20 | 88 |
| 2009 | 18 | 87 |
| 2008 | 20 | 86 |
| 2007 | 18 | 81 |
| 2006 | 15 | 86 |
| 2005 | 12 | 88 |
| 2004 | 11 | 83 |
| 2003 | 9 | 81 |
| 2002 | 9 | 83 |
| 2001 | 9 | 81 |
| 2000 | 6 | 85 |
| 1999 | 6 | 84 |
| 1998 | 5 | 82 |
| 1997 | 5 | 84 |
| 1996 | 6 | 79 |
| 1995 | 6 | 73 |
| 1994 | 4 | 77 |
| 1993 | 3 | 81 |
| 1992 | 2 | 85 |
| 1991 | 1 | 85 |
| 1990 | 1 | 85 |
| 1989 | 1 | 86 |
| 1988 | 1 | 81 |
| 1987 | 1 | 80 |
| 1986 | 1 | 81 |