| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 1328.8 | 24 |
| 2011 | 2084 | 24 |
| 2010 | 2171.3 | 23 |
| 2009 | 2477.6 | 22 |
| 2008 | 3682.6 | 22 |
| 2007 | 4718.8 | 21 |
| 2006 | 3509.5 | 20 |
| 2005 | 1947.9 | 21 |
| 2004 | 1354.6 | 21 |
| 2003 | 699.7 | 24 |
| 2002 | 488.9 | 23 |
| 2001 | 523.3 | 23 |
| 2000 | 601.2 | 24 |
| 1999 | 541.4 | 25 |
| 1998 | 426.4 | 26 |
| 1997 | 464.2 | 23 |
| 1996 | 358.8 | 23 |
| 1995 | 244.2 | 24 |
| 1994 | 88.2 | 32 |
| 1993 | 87.5 | 29 |
| 1992 | 101.5 | 25 |
| 1991 | 116.4 | 20 |
| 1990 | 140 | 18 |
| 1989 | 124.9 | 19 |
| 1988 | 48.5 | 21 |