| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 23 | 81 |
| 2015 | 21 | 98 |
| 2014 | 21 | 101 |
| 2013 | 20 | 103 |
| 2012 | 19 | 100 |
| 2011 | 18 | 102 |
| 2010 | 20 | 98 |
| 2009 | 20 | 94 |
| 2008 | 19 | 97 |
| 2007 | 13 | 103 |
| 2006 | 12 | 101 |
| 2005 | 13 | 93 |
| 2004 | 11 | 97 |
| 2003 | 10 | 97 |
| 2002 | 7 | 104 |
| 2001 | 8 | 98 |
| 2000 | 8 | 96 |
| 1999 | 9 | 91 |
| 1998 | 9 | 96 |
| 1997 | 8 | 97 |
| 1996 | 9 | 94 |
| 1995 | 9 | 88 |
| 1994 | 7 | 85 |
| 1993 | 11 | 74 |
| 1992 | 10 | 71 |
| 1991 | 10 | 71 |
| 1990 | 10 | 67 |
| 1989 | 10 | 55 |
| 1988 | 9 | 57 |
| 1987 | 11 | 52 |
| 1986 | 9 | 56 |