| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 2 | 139 |
| 2014 | 2 | 149 |
| 2013 | 2 | 152 |
| 2012 | 2 | 154 |
| 2011 | 2 | 157 |
| 2010 | 2 | 155 |
| 2009 | 2 | 152 |
| 2008 | 2 | 153 |
| 2007 | 2 | 152 |
| 2006 | 1 | 153 |
| 2005 | 1 | 149 |
| 2004 | 1 | 141 |
| 1999 | 0 | 141 |
| 1998 | 1 | 134 |
| 1997 | 1 | 133 |
| 1996 | 1 | 128 |
| 1995 | 1 | 124 |
| 1994 | 0 | 124 |
| 1993 | 0 | 124 |
| 1992 | 0 | 115 |
| 1991 | 0 | 117 |
| 1990 | 0 | 114 |
| 1989 | 0 | 112 |
| 1988 | 0 | 112 |
| 1987 | 0 | 120 |
| 1986 | 0 | 121 |