| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 60 | 28 |
| 2015 | 58.2 | 29 |
| 2014 | 73.4 | 28 |
| 2013 | 73.9 | 30 |
| 2012 | 71.4 | 27 |
| 2011 | 72.3 | 25 |
| 2010 | 65 | 25 |
| 2009 | 62 | 25 |
| 2008 | 63.7 | 25 |
| 2007 | 58.8 | 26 |
| 2006 | 50.1 | 26 |
| 2005 | 48.8 | 26 |
| 2004 | 48.9 | 24 |
| 2003 | 45.2 | 23 |
| 2002 | 40.7 | 23 |
| 2001 | 29.7 | 31 |
| 2000 | 29.2 | 29 |
| 1999 | 33.1 | 25 |
| 1998 | 33.2 | 29 |
| 1997 | 32.5 | 28 |
| 1996 | 35.4 | 27 |
| 1995 | 35.1 | 28 |
| 1994 | 34 | 26 |
| 1993 | 31.8 | 26 |
| 1992 | 38 | 23 |
| 1991 | 32.9 | 23 |
| 1990 | 33.9 | 24 |
| 1989 | 29.3 | 23 |
| 1988 | 28.9 | 21 |
| 1987 | 27.5 | 22 |
| 1986 | 21.7 | 24 |