| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 32 | 56 |
| 2015 | 28 | 83 |
| 2014 | 25 | 94 |
| 2013 | 24 | 94 |
| 2012 | 22 | 98 |
| 2011 | 19 | 100 |
| 2010 | 19 | 95 |
| 2009 | 15 | 98 |
| 2008 | 18 | 95 |
| 2007 | 19 | 88 |
| 2006 | 17 | 85 |
| 2005 | 15 | 81 |
| 2004 | 14 | 75 |
| 2003 | 13 | 72 |
| 2002 | 12 | 74 |
| 2001 | 12 | 68 |
| 2000 | 13 | 67 |
| 1999 | 11 | 67 |
| 1998 | 11 | 67 |
| 1997 | 10 | 69 |
| 1996 | 10 | 67 |
| 1995 | 9 | 66 |
| 1994 | 8 | 66 |
| 1993 | 8 | 64 |
| 1992 | 7 | 60 |
| 1991 | 5 | 66 |
| 1990 | 5 | 64 |
| 1989 | 5 | 63 |
| 1988 | 4 | 67 |
| 1987 | 4 | 66 |
| 1986 | 3 | 67 |