| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 22.37 | 155 |
| 2015 | 20.58 | 164 |
| 2014 | 19.59 | 168 |
| 2013 | 17.98 | 174 |
| 2012 | 18.24 | 172 |
| 2011 | 18.2 | 177 |
| 2010 | 15.85 | 177 |
| 2009 | 12.65 | 178 |
| 2008 | 12.58 | 180 |
| 2007 | 11.96 | 181 |
| 2006 | 8.98 | 184 |
| 2005 | 8.19 | 182 |
| 2004 | 7.03 | 182 |
| 2003 | 6.22 | 182 |
| 2002 | 5.37 | 185 |
| 2001 | 4.76 | 183 |
| 2000 | 4.39 | 184 |
| 1999 | 4.19 | 183 |
| 1998 | 3.77 | 180 |
| 1997 | 3.66 | 179 |
| 1996 | 3.16 | 181 |
| 1995 | 3.03 | 179 |
| 1994 | 2.71 | 172 |
| 1993 | 2.35 | 172 |
| 1992 | 2.51 | 168 |
| 1991 | 2.5 | 167 |
| 1990 | 3 | 164 |
| 1989 | 2.76 | 149 |
| 1988 | 2.84 | 146 |
| 1987 | 2.53 | 143 |
| 1986 | 2.01 | 141 |