| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 5.9 | 112 |
| 2015 | 6.9 | 136 |
| 2014 | 8.6 | 134 |
| 2013 | 8.1 | 137 |
| 2012 | 8.5 | 136 |
| 2011 | 8.8 | 132 |
| 2010 | 9.3 | 135 |
| 2009 | 8.6 | 132 |
| 2008 | 8.7 | 127 |
| 2007 | 10.4 | 120 |
| 2006 | 7.4 | 124 |
| 2005 | 8.3 | 118 |
| 2004 | 7.4 | 119 |
| 2003 | 8.3 | 115 |
| 2002 | 6.5 | 119 |
| 2001 | 7.5 | 114 |
| 2000 | 6.2 | 115 |
| 1999 | 5.9 | 111 |
| 1998 | 6.2 | 110 |
| 1997 | 6.3 | 107 |
| 1996 | 5.5 | 107 |
| 1995 | 5.7 | 107 |
| 1994 | 5.6 | 102 |
| 1993 | 5.8 | 99 |
| 1992 | 5.9 | 96 |
| 1991 | 6 | 94 |
| 1990 | 6.5 | 90 |
| 1989 | 6.7 | 76 |
| 1988 | 6.3 | 73 |
| 1987 | 6.6 | 73 |
| 1986 | 6.1 | 73 |