| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 1 | 165 |
| 2014 | 1 | 170 |
| 2013 | 1 | 175 |
| 2012 | 1 | 176 |
| 2011 | 1 | 178 |
| 2010 | 1 | 178 |
| 2009 | 1 | 175 |
| 2008 | 1 | 175 |
| 2007 | 1 | 179 |
| 2006 | 0 | 177 |
| 2005 | 0 | 176 |
| 2004 | 0 | 176 |
| 2003 | 0 | 175 |
| 2002 | 0 | 177 |
| 2001 | 0 | 176 |
| 2000 | 0 | 177 |
| 1999 | 0 | 171 |
| 1998 | 0 | 170 |
| 1997 | 0 | 171 |
| 1996 | 0 | 168 |
| 1995 | 0 | 169 |
| 1994 | 0 | 152 |
| 1993 | 0 | 143 |
| 1992 | 0 | 140 |
| 1991 | 0 | 140 |
| 1990 | 0 | 137 |
| 1989 | 0 | 120 |
| 1988 | 0 | 116 |
| 1987 | 0 | 114 |
| 1986 | 0 | 110 |