| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 52.8 | 128 |
| 2015 | 51.3 | 150 |
| 2014 | 53.1 | 151 |
| 2013 | 48.8 | 154 |
| 2012 | 44 | 156 |
| 2011 | 43.9 | 155 |
| 2010 | 37.2 | 157 |
| 2009 | 36.6 | 156 |
| 2008 | 36.8 | 155 |
| 2007 | 29.4 | 155 |
| 2006 | 26 | 156 |
| 2005 | 25.1 | 156 |
| 2004 | 23.1 | 155 |
| 2003 | 19.4 | 154 |
| 2002 | 16.6 | 151 |
| 2001 | 15.3 | 148 |
| 2000 | 14.7 | 148 |
| 1999 | 17.4 | 144 |
| 1998 | 18 | 144 |
| 1997 | 17.4 | 146 |
| 1996 | 16.2 | 147 |
| 1995 | 13.7 | 147 |
| 1994 | 10.2 | 144 |
| 1993 | 13.3 | 138 |
| 1992 | 18.5 | 129 |
| 1991 | 17.3 | 131 |
| 1990 | 18.2 | 128 |
| 1989 | 14.8 | 111 |
| 1988 | 15 | 108 |
| 1987 | 13.7 | 108 |
| 1986 | 11.9 | 112 |