| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 27 | 74 |
| 2015 | 25 | 89 |
| 2014 | 24 | 96 |
| 2013 | 21 | 100 |
| 2012 | 19 | 103 |
| 2011 | 23 | 97 |
| 2010 | 21 | 94 |
| 2009 | 19 | 96 |
| 2008 | 18 | 98 |
| 2007 | 14 | 101 |
| 2006 | 11 | 104 |
| 2005 | 9 | 108 |
| 2004 | 9 | 107 |
| 2003 | 8 | 106 |
| 2002 | 7 | 105 |
| 2001 | 8 | 100 |
| 2000 | 8 | 97 |
| 1999 | 8 | 96 |
| 1998 | 7 | 107 |
| 1997 | 9 | 93 |
| 1996 | 10 | 89 |
| 1995 | 10 | 87 |
| 1994 | 9 | 78 |
| 1993 | 8 | 85 |
| 1992 | 7 | 79 |
| 1991 | 6 | 90 |
| 1990 | 5 | 93 |
| 1989 | 4 | 82 |