| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 52961 | 10 |
| 2015 | 53630 | 9 |
| 2014 | 56336 | 11 |
| 2013 | 56029 | 12 |
| 2012 | 54431 | 12 |
| 2011 | 53167 | 14 |
| 2010 | 46570 | 19 |
| 2009 | 38578 | 28 |
| 2008 | 39721 | 31 |
| 2007 | 39224 | 30 |
| 2006 | 33580 | 32 |
| 2005 | 29870 | 32 |
| 2004 | 27405 | 32 |
| 2003 | 23574 | 32 |
| 2002 | 22017 | 32 |
| 2001 | 21577 | 29 |
| 2000 | 23793 | 23 |
| 1999 | 21796 | 27 |
| 1998 | 21824 | 25 |
| 1997 | 26386 | 17 |
| 1996 | 26263 | 19 |
| 1995 | 24937 | 19 |
| 1994 | 21578 | 19 |
| 1993 | 18302 | 23 |
| 1992 | 16144 | 29 |
| 1991 | 14505 | 30 |
| 1990 | 11864 | 35 |
| 1989 | 10380 | 36 |
| 1988 | 8902 | 37 |
| 1987 | 7531 | 38 |
| 1986 | 6794 | 37 |