| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 23327 | 14 |
| 2015 | 22979 | 18 |
| 2014 | 22728 | 17 |
| 2013 | 22685 | 16 |
| 2012 | 22690 | 15 |
| 2011 | 22850 | 14 |
| 2010 | 22852 | 18 |
| 2009 | 22550 | 17 |
| 2008 | 22618 | 19 |
| 2007 | 22645 | 19 |
| 2006 | 22231 | 21 |
| 2005 | 21903 | 21 |
| 2004 | 21528 | 20 |
| 2003 | 21262 | 20 |
| 2002 | 21095 | 18 |
| 2001 | 20817 | 18 |
| 2000 | 20448 | 18 |
| 1999 | 19859 | 16 |
| 1998 | 19287 | 16 |
| 1997 | 18609 | 16 |
| 1996 | 18558 | 15 |
| 1995 | 18267 | 14 |
| 1994 | 18016 | 13 |
| 1993 | 17780 | 13 |
| 1992 | 17861 | 13 |
| 1991 | 17743 | 15 |
| 1990 | 17639 | 16 |
| 1989 | 17292 | 15 |
| 1988 | 16854 | 15 |
| 1987 | 16408 | 14 |
| 1986 | 15978 | 14 |