| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 32 | 68 |
| 2015 | 33 | 79 |
| 2014 | 39 | 77 |
| 2013 | 44 | 74 |
| 2012 | 42 | 72 |
| 2011 | 42 | 73 |
| 2010 | 29 | 80 |
| 2009 | 25 | 85 |
| 2008 | 28 | 82 |
| 2007 | 20 | 92 |
| 2006 | 17 | 90 |
| 2005 | 15 | 89 |
| 2004 | 15 | 84 |
| 2003 | 12 | 89 |
| 2002 | 11 | 91 |
| 2001 | 12 | 82 |
| 2000 | 14 | 75 |
| 1999 | 14 | 76 |
| 1998 | 18 | 72 |
| 1997 | 16 | 75 |
| 1996 | 16 | 73 |
| 1995 | 17 | 73 |
| 1994 | 14 | 66 |
| 1993 | 11 | 70 |
| 1992 | 11 | 66 |
| 1991 | 10 | 73 |
| 1990 | 9 | 76 |
| 1989 | 9 | 60 |
| 1988 | 10 | 55 |
| 1987 | 10 | 53 |
| 1986 | 7 | 58 |