| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 39513 | 1 |
| 2015 | 39226 | 2 |
| 2014 | 38815 | 2 |
| 2013 | 38509 | 2 |
| 2012 | 37956 | 2 |
| 2011 | 37168 | 2 |
| 2010 | 36789 | 3 |
| 2009 | 35899 | 2 |
| 2008 | 36345 | 2 |
| 2007 | 36194 | 2 |
| 2006 | 34727 | 3 |
| 2005 | 33353 | 4 |
| 2004 | 32165 | 4 |
| 2003 | 30684 | 5 |
| 2002 | 29910 | 5 |
| 2001 | 29157 | 5 |
| 2000 | 28713 | 4 |
| 1999 | 27740 | 4 |
| 1998 | 26925 | 4 |
| 1997 | 26341 | 3 |
| 1996 | 25683 | 3 |
| 1995 | 24278 | 4 |
| 1994 | 23554 | 4 |
| 1993 | 22910 | 4 |
| 1992 | 22535 | 4 |
| 1991 | 22142 | 4 |
| 1990 | 21794 | 4 |
| 1989 | 21719 | 4 |
| 1988 | 21942 | 4 |
| 1987 | 22537 | 3 |
| 1986 | 22783 | 2 |