| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 37293 | 24 |
| 2015 | 35729 | 26 |
| 2014 | 37583 | 30 |
| 2013 | 36394 | 33 |
| 2012 | 32570 | 35 |
| 2011 | 33657 | 36 |
| 2010 | 30662 | 38 |
| 2009 | 27796 | 39 |
| 2008 | 29657 | 39 |
| 2007 | 25009 | 42 |
| 2006 | 21905 | 45 |
| 2005 | 20611 | 44 |
| 2004 | 19888 | 44 |
| 2003 | 18947 | 41 |
| 2002 | 18431 | 38 |
| 2001 | 20306 | 33 |
| 2000 | 21052 | 32 |
| 1999 | 19137 | 35 |
| 1998 | 19400 | 29 |
| 1997 | 19627 | 27 |
| 1996 | 19286 | 29 |
| 1995 | 18029 | 31 |
| 1994 | 13830 | 35 |
| 1993 | 12531 | 36 |
| 1992 | 12838 | 35 |
| 1991 | 11956 | 35 |
| 1990 | 11264 | 36 |
| 1989 | 9872 | 37 |
| 1988 | 9881 | 35 |
| 1987 | 8120 | 36 |
| 1986 | 6909 | 36 |