| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 50 | 55 |
| 2015 | 47 | 62 |
| 2014 | 57 | 62 |
| 2013 | 57 | 63 |
| 2012 | 40 | 75 |
| 2011 | 50 | 65 |
| 2010 | 41 | 68 |
| 2009 | 27 | 77 |
| 2008 | 40 | 68 |
| 2007 | 27 | 78 |
| 2006 | 19 | 86 |
| 2005 | 16 | 88 |
| 2004 | 15 | 86 |
| 2003 | 11 | 92 |
| 2002 | 9 | 96 |
| 2001 | 10 | 88 |
| 2000 | 12 | 80 |
| 1999 | 13 | 81 |
| 1998 | 14 | 80 |
| 1997 | 16 | 74 |
| 1996 | 18 | 69 |
| 1995 | 17 | 72 |
| 1994 | 14 | 65 |
| 1993 | 12 | 66 |
| 1992 | 11 | 68 |
| 1991 | 11 | 68 |