| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 21 | 94 |
| 2014 | 26 | 93 |
| 2013 | 25 | 92 |
| 2012 | 21 | 100 |
| 2011 | 20 | 99 |
| 2010 | 17 | 99 |
| 2009 | 19 | 89 |
| 2008 | 26 | 82 |
| 2007 | 17 | 93 |
| 2006 | 14 | 94 |
| 2005 | 14 | 84 |
| 2004 | 14 | 74 |
| 2003 | 12 | 76 |
| 2002 | 13 | 70 |
| 2001 | 11 | 69 |
| 2000 | 10 | 71 |
| 1999 | 7 | 85 |
| 1998 | 8 | 77 |
| 1997 | 9 | 72 |
| 1996 | 10 | 66 |
| 1995 | 5 | 83 |
| 1994 | 5 | 79 |
| 1993 | 7 | 68 |
| 1992 | 9 | 54 |
| 1991 | 11 | 45 |
| 1990 | 10 | 46 |
| 1989 | 10 | 46 |
| 1988 | 9 | 45 |
| 1987 | 10 | 43 |
| 1986 | 9 | 42 |