| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2015 | 21461 | 21 |
| 2014 | 21274 | 22 |
| 2013 | 20956 | 22 |
| 2012 | 20394 | 22 |
| 2011 | 20050 | 23 |
| 2010 | 19567 | 26 |
| 2009 | 19333 | 24 |
| 2008 | 19258 | 24 |
| 2007 | 19558 | 24 |
| 2006 | 19008 | 24 |
| 2005 | 18673 | 23 |
| 2004 | 18051 | 23 |
| 2003 | 17389 | 25 |
| 2002 | 16699 | 27 |
| 2001 | 16186 | 24 |
| 2000 | 15856 | 23 |
| 1999 | 15729 | 22 |
| 1998 | 15348 | 21 |
| 1997 | 15044 | 22 |
| 1996 | 14839 | 22 |
| 1995 | 14355 | 22 |
| 1994 | 13985 | 21 |
| 1993 | 13322 | 23 |
| 1992 | 12976 | 24 |
| 1991 | 13071 | 21 |
| 1990 | 14054 | 20 |
| 1989 | 14127 | 19 |
| 1988 | 14052 | 18 |
| 1987 | 13690 | 18 |
| 1986 | 13427 | 18 |