| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 23477 | 13 |
| 2015 | 23258 | 16 |
| 2014 | 22427 | 19 |
| 2013 | 22123 | 18 |
| 2012 | 22256 | 16 |
| 2011 | 22587 | 17 |
| 2010 | 22882 | 17 |
| 2009 | 22968 | 14 |
| 2008 | 24630 | 14 |
| 2007 | 25135 | 12 |
| 2006 | 24267 | 13 |
| 2005 | 23367 | 13 |
| 2004 | 22307 | 15 |
| 2003 | 21922 | 15 |
| 2002 | 21659 | 16 |
| 2001 | 21237 | 17 |
| 2000 | 20622 | 16 |
| 1999 | 18903 | 19 |
| 1998 | 17469 | 19 |
| 1997 | 16374 | 19 |
| 1996 | 15535 | 19 |
| 1995 | 14571 | 20 |
| 1994 | 14158 | 20 |
| 1993 | 13619 | 21 |
| 1992 | 13301 | 22 |
| 1991 | 13016 | 22 |
| 1990 | 12859 | 22 |
| 1989 | 12691 | 21 |
| 1988 | 11867 | 20 |
| 1987 | 11309 | 20 |
| 1986 | 10946 | 20 |