| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 62.5 | 64 |
| 2015 | 61.5 | 74 |
| 2014 | 60.2 | 75 |
| 2013 | 58.7 | 78 |
| 2012 | 56 | 77 |
| 2011 | 52.8 | 77 |
| 2010 | 50.9 | 82 |
| 2009 | 49.4 | 79 |
| 2008 | 47 | 79 |
| 2007 | 43 | 80 |
| 2006 | 41.1 | 79 |
| 2005 | 40.2 | 77 |
| 2004 | 40.2 | 76 |
| 2003 | 39.2 | 73 |
| 2002 | 41.2 | 72 |
| 2001 | 45.5 | 69 |
| 2000 | 46.8 | 67 |
| 1999 | 46.9 | 64 |
| 1998 | 46.7 | 64 |
| 1997 | 44.9 | 64 |
| 1996 | 43.9 | 64 |
| 1995 | 41.8 | 64 |
| 1994 | 41.7 | 60 |
| 1993 | 39.9 | 62 |
| 1992 | 39.6 | 60 |
| 1991 | 39 | 59 |
| 1990 | 38.5 | 57 |
| 1989 | 37.8 | 48 |
| 1988 | 37.2 | 48 |
| 1987 | 38.1 | 47 |
| 1986 | 36.1 | 46 |