| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 43681 | 15 |
| 2015 | 42351 | 18 |
| 2014 | 40247 | 28 |
| 2013 | 38358 | 32 |
| 2012 | 36708 | 33 |
| 2011 | 35142 | 35 |
| 2010 | 32550 | 35 |
| 2009 | 30697 | 34 |
| 2008 | 31516 | 37 |
| 2007 | 30594 | 38 |
| 2006 | 28224 | 38 |
| 2005 | 26650 | 35 |
| 2004 | 24928 | 35 |
| 2003 | 23977 | 31 |
| 2002 | 24666 | 26 |
| 2001 | 25230 | 19 |
| 2000 | 25757 | 19 |
| 1999 | 25092 | 22 |
| 1998 | 25809 | 19 |
| 1997 | 27330 | 13 |
| 1996 | 24818 | 21 |
| 1995 | 23497 | 20 |
| 1994 | 22503 | 18 |
| 1993 | 20396 | 18 |
| 1992 | 17976 | 25 |
| 1991 | 15466 | 27 |
| 1990 | 13486 | 33 |
| 1989 | 12098 | 31 |
| 1988 | 10610 | 33 |
| 1987 | 9071 | 34 |
| 1986 | 7435 | 34 |