| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 22 | 156 |
| 2015 | 23.35 | 162 |
| 2014 | 25.21 | 166 |
| 2013 | 25.32 | 170 |
| 2012 | 26.78 | 166 |
| 2011 | 27.92 | 167 |
| 2010 | 23.94 | 168 |
| 2009 | 18.64 | 173 |
| 2008 | 18.69 | 174 |
| 2007 | 18.21 | 171 |
| 2006 | 18 | 172 |
| 2005 | 16.82 | 168 |
| 2004 | 15.11 | 168 |
| 2003 | 11.58 | 169 |
| 2002 | 7.76 | 175 |
| 2001 | 8.26 | 170 |
| 2000 | 8.87 | 167 |
| 1999 | 9.13 | 164 |
| 1998 | 9.28 | 165 |
| 1997 | 9.98 | 160 |
| 1996 | 9.46 | 163 |
| 1995 | 10.02 | 161 |
| 1994 | 8.78 | 154 |
| 1993 | 8.36 | 152 |
| 1992 | 8.31 | 150 |
| 1991 | 7.04 | 152 |
| 1990 | 5.96 | 152 |
| 1989 | 4.95 | 140 |
| 1988 | 4.7 | 139 |
| 1987 | 4.03 | 137 |
| 1986 | 3.19 | 135 |