| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 10 | 61 |
| 2015 | 10 | 68 |
| 2014 | 11.9 | 69 |
| 2013 | 12 | 69 |
| 2012 | 11.6 | 69 |
| 2011 | 13 | 67 |
| 2010 | 12.7 | 68 |
| 2009 | 14.2 | 67 |
| 2008 | 15.8 | 62 |
| 2007 | 13.7 | 60 |
| 2006 | 11.9 | 60 |
| 2005 | 11.5 | 58 |
| 2004 | 11 | 56 |
| 2003 | 9.7 | 55 |
| 2002 | 8.1 | 57 |
| 2001 | 7.7 | 57 |
| 2000 | 6.9 | 59 |
| 1999 | 7.4 | 60 |
| 1998 | 7.4 | 56 |
| 1997 | 7.7 | 57 |
| 1996 | 7.5 | 55 |
| 1995 | 7 | 57 |
| 1994 | 6.3 | 55 |
| 1993 | 6 | 54 |
| 1992 | 6.7 | 51 |
| 1991 | 6.2 | 52 |
| 1990 | 5.9 | 56 |
| 1989 | 4.3 | 55 |
| 1988 | 4.5 | 53 |
| 1987 | 4.4 | 54 |
| 1986 | 4.1 | 49 |