| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 19053 | 20 |
| 2015 | 18544 | 27 |
| 2014 | 18101 | 27 |
| 2013 | 17781 | 27 |
| 2012 | 18850 | 24 |
| 2011 | 19396 | 24 |
| 2010 | 20030 | 24 |
| 2009 | 19900 | 23 |
| 2008 | 21828 | 22 |
| 2007 | 20746 | 22 |
| 2006 | 19226 | 22 |
| 2005 | 18720 | 22 |
| 2004 | 18356 | 22 |
| 2003 | 17354 | 26 |
| 2002 | 17083 | 25 |
| 2001 | 16824 | 23 |
| 2000 | 16370 | 22 |
| 1999 | 15419 | 23 |
| 1998 | 15120 | 23 |
| 1997 | 14480 | 24 |
| 1996 | 14336 | 23 |
| 1995 | 14123 | 23 |
| 1994 | 11143 | 27 |
| 1993 | 10648 | 27 |
| 1992 | 11439 | 25 |
| 1991 | 11386 | 25 |
| 1990 | 10630 | 25 |
| 1989 | 9967 | 24 |
| 1988 | 9457 | 23 |
| 1987 | 8649 | 26 |
| 1986 | 8292 | 25 |