| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 791.6 | 6 |
| 2015 | 2034.6 | 3 |
| 2014 | 867.7 | 6 |
| 2013 | 499.6 | 13 |
| 2012 | 409.6 | 14 |
| 2011 | 236.6 | 19 |
| 2010 | 377.6 | 14 |
| 2009 | 539.4 | 7 |
| 2008 | 232.6 | 20 |
| 2007 | 599.4 | 13 |
| 2006 | 220.8 | 18 |
| 2005 | 470.3 | 8 |
| 2004 | -109.9 | 193 |
| 2003 | 224.1 | 8 |
| 2002 | 294.8 | 7 |
| 2001 | 95.7 | 17 |
| 2000 | 255 | 12 |
| 1999 | 183.2 | 13 |
| 1998 | 110.3 | 14 |
| 1997 | 27.4 | 34 |
| 1996 | 26.2 | 26 |
| 1995 | 14.5 | 34 |
| 1994 | 8.4 | 39 |
| 1993 | 11.2 | 30 |
| 1992 | 14.4 | 22 |
| 1991 | 13.6 | 23 |
| 1990 | 6.3 | 33 |
| 1989 | 0.9 | 51 |
| 1988 | 0.9 | 51 |
| 1987 | 0.9 | 45 |
| 1986 | -.4 | 135 |