| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 10.16 | 166 |
| 2015 | 9.84 | 176 |
| 2014 | 9.11 | 179 |
| 2013 | 8.43 | 185 |
| 2012 | 8 | 185 |
| 2011 | 7.79 | 189 |
| 2010 | 7.71 | 187 |
| 2009 | 7.71 | 187 |
| 2008 | 8.26 | 187 |
| 2007 | 7.59 | 186 |
| 2006 | 6.99 | 186 |
| 2005 | 6.95 | 184 |
| 2004 | 5.99 | 184 |
| 2003 | 5.91 | 183 |
| 2002 | 5.4 | 184 |
| 2001 | 5.2 | 182 |
| 2000 | 5.2 | 183 |
| 1999 | 4.82 | 181 |
| 1998 | 4.46 | 179 |
| 1997 | 3.92 | 178 |
| 1996 | 3.67 | 178 |
| 1995 | 3.42 | 177 |
| 1994 | 3.25 | 169 |
| 1993 | 3.1 | 167 |
| 1992 | 3.1 | 164 |
| 1991 | 3.01 | 164 |
| 1990 | 2.78 | 165 |
| 1989 | 2.67 | 151 |
| 1988 | 2.36 | 150 |
| 1987 | 2.15 | 148 |
| 1986 | 1.88 | 143 |