| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 1564.5 | 23 |
| 2011 | 2537.7 | 22 |
| 2010 | 2821.4 | 21 |
| 2009 | 2522.7 | 21 |
| 2008 | 2709 | 23 |
| 2007 | 3842.3 | 23 |
| 2006 | 1843.8 | 24 |
| 2005 | 1198.2 | 28 |
| 2004 | 813.1 | 26 |
| 2003 | 878.6 | 22 |
| 2002 | 561.3 | 20 |
| 2001 | 633.9 | 22 |
| 2000 | 914.9 | 22 |
| 1999 | 979.9 | 19 |
| 1998 | 507.4 | 23 |
| 1997 | 639.5 | 19 |
| 1996 | 427.4 | 21 |
| 1995 | 604.6 | 16 |
| 1994 | 810.5 | 18 |
| 1993 | 816.2 | 12 |
| 1992 | 140.8 | 24 |
| 1991 | 180.7 | 18 |
| 1990 | 202.9 | 15 |
| 1989 | 137.1 | 17 |
| 1988 | 44.7 | 22 |