| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 13 | 108 |
| 2014 | 22 | 97 |
| 2013 | 39 | 79 |
| 2012 | 37 | 79 |
| 2011 | 29 | 83 |
| 2010 | 27 | 80 |
| 2009 | 18 | 91 |
| 2008 | 18 | 96 |
| 2007 | 19 | 87 |
| 2006 | 16 | 89 |
| 2005 | 13 | 90 |
| 2004 | 11 | 83 |
| 2003 | 10 | 81 |
| 2002 | 8 | 84 |
| 2001 | 7 | 86 |
| 2000 | 8 | 79 |
| 1999 | 7 | 81 |
| 1998 | 8 | 78 |
| 1997 | 9 | 71 |
| 1996 | 8 | 75 |
| 1995 | 6 | 75 |
| 1994 | 6 | 73 |
| 1993 | 8 | 63 |
| 1992 | 7 | 61 |
| 1991 | 5 | 63 |
| 1990 | 4 | 72 |
| 1989 | 4 | 73 |
| 1988 | 4 | 66 |
| 1987 | 4 | 67 |
| 1986 | 3 | 70 |