| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 44 | 147 |
| 2015 | 40.88 | 156 |
| 2014 | 44.83 | 158 |
| 2013 | 40.81 | 163 |
| 2012 | 38.67 | 162 |
| 2011 | 37.56 | 164 |
| 2010 | 31.73 | 164 |
| 2009 | 31.63 | 164 |
| 2008 | 31.63 | 165 |
| 2007 | 25.23 | 167 |
| 2006 | 22.03 | 168 |
| 2005 | 21.15 | 165 |
| 2004 | 19.37 | 164 |
| 2003 | 16.74 | 161 |
| 2002 | 14.75 | 159 |
| 2001 | 13.32 | 158 |
| 2000 | 12.94 | 157 |
| 1999 | 15.76 | 150 |
| 1998 | 15.87 | 153 |
| 1997 | 14.99 | 154 |
| 1996 | 14.65 | 152 |
| 1995 | 13.09 | 155 |
| 1994 | 9.83 | 150 |
| 1993 | 12.33 | 146 |
| 1992 | 16.93 | 137 |
| 1991 | 16.02 | 139 |
| 1990 | 16.28 | 138 |
| 1989 | 13.53 | 125 |
| 1988 | 13.79 | 125 |
| 1987 | 12.49 | 121 |
| 1986 | 10.61 | 124 |