| 时间 | 值 （美元/人） | 世界排名 |
|---|---|---|
| 2016 | 52 | 81 |
| 2015 | 54 | 87 |
| 2014 | 59 | 89 |
| 2013 | 54 | 93 |
| 2012 | 49 | 93 |
| 2011 | 40 | 97 |
| 2010 | 33 | 103 |
| 2009 | 35 | 98 |
| 2008 | 34 | 103 |
| 2007 | 23 | 104 |
| 2006 | 19 | 105 |
| 2005 | 19 | 104 |
| 2004 | 19 | 101 |
| 2003 | 20 | 98 |
| 2002 | 19 | 95 |
| 2001 | 22 | 87 |
| 2000 | 21 | 89 |
| 1999 | 22 | 83 |
| 1998 | 28 | 77 |
| 1997 | 23 | 85 |
| 1996 | 19 | 83 |
| 1995 | 19 | 82 |
| 1994 | 18 | 82 |
| 1993 | 15 | 84 |
| 1992 | 20 | 73 |
| 1991 | 21 | 71 |
| 1990 | 20 | 75 |
| 1989 | 15 | 76 |
| 1988 | 14 | 81 |
| 1987 | 16 | 71 |
| 1986 | 15 | 64 |