| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 31 | 96 |
| 2015 | 30 | 114 |
| 2014 | 34 | 113 |
| 2013 | 34 | 115 |
| 2012 | 33 | 112 |
| 2011 | 30 | 119 |
| 2010 | 22 | 123 |
| 2009 | 20 | 120 |
| 2008 | 24 | 118 |
| 2007 | 21 | 120 |
| 2006 | 17 | 121 |
| 2005 | 15 | 117 |
| 2004 | 12 | 125 |
| 2003 | 10 | 128 |
| 2002 | 8 | 128 |
| 2001 | 7 | 129 |
| 2000 | 6 | 128 |
| 1999 | 6 | 126 |
| 1998 | 8 | 122 |
| 1997 | 8 | 120 |
| 1996 | 7 | 117 |
| 1995 | 4 | 129 |
| 1994 | 3 | 123 |
| 1993 | 6 | 101 |
| 1992 | 9 | 87 |
| 1991 | 22 | 65 |
| 1990 | 24 | 60 |