| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2012 | 250.1 | 103 |
| 2011 | 201.2 | 110 |
| 2010 | 153.9 | 110 |
| 2009 | 142.8 | 111 |
| 2008 | 147.1 | 113 |
| 2007 | 80.2 | 130 |
| 2006 | 63.5 | 132 |
| 2005 | 67.1 | 125 |
| 2004 | 66.9 | 120 |
| 2003 | 56.4 | 119 |
| 2002 | 37.6 | 133 |
| 2001 | 33.7 | 129 |
| 2000 | 24.8 | 134 |
| 1999 | 31.2 | 134 |
| 1998 | 36 | 127 |
| 1997 | 30.8 | 130 |
| 1996 | 24 | 135 |
| 1995 | 24.9 | 132 |
| 1994 | 25.7 | 122 |
| 1993 | 24.4 | 121 |
| 1992 | 22.7 | 123 |
| 1991 | 28.3 | 118 |