| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 672.5 | 32 |
| 2011 | 958.9 | 32 |
| 2010 | 774.6 | 32 |
| 2009 | 557.8 | 34 |
| 2008 | 679.5 | 37 |
| 2007 | 845.7 | 39 |
| 2006 | 550.4 | 38 |
| 2005 | 299.7 | 40 |
| 2004 | 165.7 | 39 |
| 2003 | 85 | 40 |
| 2002 | 58.4 | 40 |
| 2001 | 74.3 | 38 |
| 2000 | 146.3 | 34 |
| 1999 | 111.5 | 39 |
| 1998 | 89.2 | 42 |
| 1997 | 79.5 | 41 |
| 1996 | 55.4 | 41 |
| 1995 | 27.7 | 43 |
| 1994 | 51.3 | 38 |
| 1993 | 21.7 | 39 |
| 1992 | 1.7 | 46 |
| 1991 | 0.3 | 54 |