| 时间 | 值 （美元） | 世界排名 |
|---|---|---|
| 2015 | 1613 | 108 |
| 2014 | 1633 | 109 |
| 2013 | 1667 | 113 |
| 2012 | 1414 | 115 |
| 2011 | 1452 | 115 |
| 2010 | 1539 | 124 |
| 2009 | 1736 | 106 |
| 2008 | 1354 | 113 |
| 2007 | 1724 | 105 |
| 2006 | 1286 | 109 |
| 2005 | 1624 | 96 |
| 2004 | 1526 | 97 |
| 2003 | 1453 | 97 |
| 2002 | 1291 | 97 |
| 2001 | 1316 | 93 |
| 2000 | 954 | 99 |
| 1999 | 961 | 95 |
| 1998 | 1048 | 93 |
| 1997 | 1067 | 91 |
| 1996 | 1133 | 87 |
| 1995 | 967 | 90 |
| 1994 | 934 | 87 |
| 1993 | 1004 | 81 |
| 1992 | 1050 | 79 |
| 1991 | 967 | 81 |
| 1990 | 962 | 80 |
| 1989 | 805 | 71 |
| 1988 | 857 | 67 |
| 1987 | 791 | 69 |
| 1986 | 1029 | 61 |