| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 21 | 146 |
| 2015 | 19 | 156 |
| 2014 | 20 | 157 |
| 2013 | 17 | 161 |
| 2012 | 16 | 163 |
| 2011 | 15 | 163 |
| 2010 | 11 | 161 |
| 2009 | 10 | 162 |
| 2008 | 14 | 157 |
| 2007 | 11 | 158 |
| 2006 | 9 | 160 |
| 2005 | 7 | 159 |
| 2004 | 6 | 161 |
| 2003 | 5 | 161 |
| 2002 | 4 | 165 |
| 2001 | 4 | 164 |
| 2000 | 4 | 164 |
| 1999 | 4 | 164 |
| 1998 | 4 | 164 |
| 1997 | 3 | 163 |
| 1996 | 3 | 165 |
| 1995 | 3 | 164 |
| 1994 | 2 | 165 |
| 1993 | 2 | 154 |
| 1992 | 2 | 155 |
| 1991 | 2 | 149 |
| 1990 | 1 | 150 |
| 1989 | 1 | 151 |
| 1988 | 1 | 155 |
| 1987 | 1 | 153 |
| 1986 | 0 | 160 |