| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 8345.3 | 12 |
| 2011 | 9613.1 | 13 |
| 2010 | 9011 | 13 |
| 2009 | 6491.9 | 15 |
| 2008 | 7277.9 | 15 |
| 2007 | 5849.5 | 19 |
| 2006 | 2545.1 | 22 |
| 2005 | 1542.3 | 23 |
| 2004 | 935.8 | 25 |
| 2003 | 604.4 | 27 |
| 2002 | 482 | 24 |
| 2001 | 650.9 | 21 |
| 2000 | 1012.8 | 19 |
| 1999 | 872.8 | 20 |
| 1998 | 1466.8 | 16 |
| 1997 | 2024.5 | 12 |
| 1996 | 1121.1 | 16 |
| 1995 | 791.9 | 14 |
| 1994 | 1095 | 13 |
| 1993 | 574.1 | 17 |
| 1992 | 205.3 | 19 |
| 1991 | 133.7 | 19 |
| 1990 | 56 | 25 |
| 1989 | 167.6 | 15 |
| 1988 | 179.8 | 13 |