| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 24856 | 10 |
| 2015 | 24551 | 14 |
| 2014 | 23640 | 14 |
| 2013 | 23048 | 14 |
| 2012 | 22132 | 18 |
| 2011 | 21509 | 21 |
| 2010 | 19978 | 25 |
| 2009 | 18965 | 25 |
| 2008 | 18972 | 25 |
| 2007 | 18730 | 27 |
| 2006 | 17388 | 28 |
| 2005 | 16495 | 30 |
| 2004 | 16000 | 30 |
| 2003 | 15053 | 30 |
| 2002 | 15261 | 29 |
| 2001 | 15490 | 26 |
| 2000 | 15389 | 25 |
| 1999 | 14855 | 25 |
| 1998 | 14842 | 24 |
| 1997 | 15837 | 20 |
| 1996 | 15131 | 20 |
| 1995 | 15250 | 19 |
| 1994 | 15306 | 19 |
| 1993 | 14699 | 19 |
| 1992 | 13866 | 20 |
| 1991 | 12878 | 23 |
| 1990 | 11884 | 24 |
| 1989 | 11220 | 23 |
| 1988 | 10919 | 22 |
| 1987 | 10068 | 22 |
| 1986 | 9191 | 22 |