| 时间 | 值 （美元/人） | 世界排名 |
|---|---|---|
| 2016 | 34 | 96 |
| 2015 | 34 | 102 |
| 2014 | 36 | 106 |
| 2013 | 36 | 105 |
| 2012 | 40 | 99 |
| 2011 | 32 | 103 |
| 2010 | 20 | 110 |
| 2009 | 14 | 117 |
| 2008 | 25 | 108 |
| 2007 | 22 | 106 |
| 2006 | 15 | 114 |
| 2005 | 12 | 113 |
| 2004 | 11 | 112 |
| 2003 | 10 | 115 |
| 2002 | 10 | 108 |
| 2001 | 10 | 106 |
| 2000 | 10 | 103 |
| 1999 | 8 | 107 |
| 1998 | 8 | 110 |
| 1997 | 8 | 114 |
| 1996 | 9 | 108 |
| 1995 | 9 | 106 |
| 1994 | 7 | 105 |
| 1993 | 6 | 111 |
| 1992 | 12 | 86 |
| 1991 | 42 | 58 |
| 1990 | 54 | 52 |
| 1989 | 132 | 36 |
| 1988 | 144 | 35 |
| 1987 | 130 | 34 |