| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 467.3 | 34 |
| 2011 | 569 | 33 |
| 2010 | 543.1 | 33 |
| 2009 | 375.7 | 38 |
| 2008 | 365.6 | 43 |
| 2007 | 444.7 | 43 |
| 2006 | 287.5 | 44 |
| 2005 | 188.7 | 45 |
| 2004 | 115.9 | 43 |
| 2003 | 65.4 | 43 |
| 2002 | 31.2 | 43 |
| 2001 | 42.2 | 41 |
| 2000 | 60.8 | 44 |
| 1999 | 68.7 | 42 |
| 1998 | 44.2 | 45 |
| 1997 | 74.3 | 43 |
| 1996 | 84.6 | 34 |
| 1995 | 110.7 | 32 |
| 1994 | 52.6 | 36 |
| 1993 | 28 | 36 |
| 1992 | 20.3 | 38 |
| 1991 | 19 | 36 |
| 1990 | 7.8 | 35 |
| 1989 | 8.7 | 32 |
| 1988 | 6.1 | 30 |