| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 242.3 | 50 |
| 2014 | 275 | 46 |
| 2013 | 295.7 | 43 |
| 2012 | 329.5 | 41 |
| 2011 | 336.2 | 41 |
| 2010 | 321.5 | 39 |
| 2009 | 287.3 | 41 |
| 2008 | 285.2 | 40 |
| 2007 | 230 | 45 |
| 2006 | 146.7 | 54 |
| 2005 | 108.1 | 58 |
| 2004 | 97.8 | 59 |
| 2003 | 14.7 | 97 |
| 2002 | 19.3 | 90 |
| 2001 | 18.3 | 93 |
| 2000 | 20.8 | 85 |
| 1999 | 20.4 | 82 |
| 1998 | 20.1 | 82 |
| 1997 | 19.8 | 82 |
| 1996 | 19.4 | 82 |
| 1995 | 18.9 | 83 |
| 1994 | 18.9 | 77 |
| 1993 | 18.6 | 76 |
| 1992 | 18.1 | 72 |
| 1991 | 17.6 | 69 |
| 1990 | 17.4 | 69 |
| 1989 | 17.1 | 59 |
| 1988 | 16.7 | 60 |
| 1987 | 16.4 | 60 |
| 1986 | 16.1 | 59 |