| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2014 | 2 | 148 |
| 2013 | 2 | 151 |
| 2012 | 2 | 153 |
| 2011 | 2 | 151 |
| 2010 | 1 | 154 |
| 2009 | 1 | 158 |
| 2008 | 1 | 157 |
| 2007 | 1 | 159 |
| 2006 | 1 | 159 |
| 2005 | 1 | 159 |
| 2004 | 1 | 161 |
| 2003 | 1 | 161 |
| 2002 | 1 | 160 |
| 2001 | 1 | 162 |
| 2000 | 1 | 161 |
| 1999 | 1 | 157 |
| 1998 | 1 | 155 |
| 1997 | 0 | 163 |
| 1996 | 0 | 161 |
| 1995 | 0 | 163 |
| 1994 | 0 | 146 |
| 1993 | 0 | 141 |
| 1992 | 0 | 138 |
| 1991 | 0 | 136 |
| 1990 | 0 | 134 |
| 1989 | 0 | 114 |
| 1988 | 0 | 112 |
| 1987 | 0 | 113 |
| 1986 | 0 | 107 |