| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 60.6 | 66 |
| 2015 | 56 | 78 |
| 2014 | 54.1 | 78 |
| 2013 | 50.8 | 81 |
| 2012 | 51.3 | 82 |
| 2011 | 51 | 79 |
| 2010 | 54.3 | 80 |
| 2009 | 60.9 | 73 |
| 2008 | 55.2 | 74 |
| 2007 | 44.6 | 79 |
| 2006 | 41.5 | 78 |
| 2005 | 36.1 | 81 |
| 2004 | 37 | 78 |
| 2003 | 38.6 | 75 |
| 2002 | 37.7 | 76 |
| 2001 | 36.3 | 73 |
| 2000 | 35.8 | 72 |
| 1999 | 35.4 | 68 |
| 1998 | 34.6 | 68 |
| 1997 | 35 | 68 |
| 1996 | 32.1 | 68 |
| 1995 | 31 | 69 |
| 1994 | 28.6 | 65 |
| 1993 | 25.6 | 67 |
| 1992 | 24.1 | 65 |
| 1991 | 24 | 62 |
| 1990 | 25.6 | 60 |
| 1989 | 31.7 | 50 |
| 1988 | 32.6 | 50 |
| 1987 | 32.2 | 50 |
| 1986 | 28.5 | 49 |