| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2016 | 19849 | 19 |
| 2015 | 19045 | 24 |
| 2014 | 18625 | 25 |
| 2013 | 18209 | 26 |
| 2012 | 17876 | 27 |
| 2011 | 17697 | 27 |
| 2010 | 17403 | 31 |
| 2009 | 16914 | 29 |
| 2008 | 17145 | 30 |
| 2007 | 17209 | 30 |
| 2006 | 16178 | 31 |
| 2005 | 15681 | 31 |
| 2004 | 15429 | 31 |
| 2003 | 14915 | 31 |
| 2002 | 15162 | 30 |
| 2001 | 15231 | 27 |
| 2000 | 14998 | 26 |
| 1999 | 14205 | 26 |
| 1998 | 13994 | 26 |
| 1997 | 13530 | 26 |
| 1996 | 13323 | 26 |
| 1995 | 12865 | 26 |