| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 14.49 | 161 |
| 2015 | 13.56 | 173 |
| 2014 | 12.74 | 176 |
| 2013 | 11.96 | 181 |
| 2012 | 12.16 | 179 |
| 2011 | 11.42 | 183 |
| 2010 | 11.48 | 181 |
| 2009 | 12.18 | 179 |
| 2008 | 13.6 | 179 |
| 2007 | 13.02 | 179 |
| 2006 | 11.49 | 180 |
| 2005 | 10.15 | 177 |
| 2004 | 9.14 | 178 |
| 2003 | 8.5 | 175 |
| 2002 | 8.1 | 174 |
| 2001 | 7.96 | 172 |
| 2000 | 8.25 | 171 |
| 1999 | 7.66 | 170 |
| 1998 | 7.28 | 170 |
| 1997 | 6.81 | 169 |
| 1996 | 6.34 | 172 |
| 1995 | 5.77 | 171 |
| 1994 | 5.89 | 160 |
| 1993 | 5.35 | 158 |
| 1992 | 4.99 | 156 |
| 1991 | 4.82 | 155 |
| 1990 | 4.59 | 154 |
| 1989 | 4.39 | 141 |
| 1988 | 3.99 | 141 |
| 1987 | 3.37 | 140 |
| 1986 | 2.9 | 136 |