| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2015 | 39569 | 21 |
| 2014 | 45317 | 22 |
| 2013 | 43967 | 25 |
| 2012 | 42399 | 26 |
| 2011 | 44212 | 27 |
| 2010 | 40533 | 27 |
| 2009 | 41277 | 22 |
| 2008 | 41023 | 28 |
| 2007 | 36233 | 33 |
| 2006 | 32035 | 34 |
| 2005 | 29089 | 33 |
| 2004 | 28498 | 31 |
| 2003 | 24802 | 30 |
| 2002 | 20653 | 34 |
| 2001 | 19275 | 35 |
| 2000 | 19004 | 35 |
| 1999 | 20170 | 32 |
| 1998 | 20497 | 28 |
| 1997 | 19145 | 28 |
| 1996 | 21422 | 25 |
| 1995 | 21666 | 22 |
| 1994 | 18124 | 24 |
| 1993 | 16797 | 27 |
| 1992 | 18769 | 23 |
| 1991 | 18315 | 24 |
| 1990 | 18327 | 23 |
| 1989 | 16814 | 20 |
| 1988 | 16398 | 20 |
| 1987 | 14554 | 20 |
| 1986 | 11271 | 24 |