| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 49.8 | 32 |
| 2015 | 80.1 | 35 |
| 2014 | -7.5 | 193 |
| 2013 | -60.3 | 193 |
| 2012 | 496 | 11 |
| 2011 | -119.2 | 194 |
| 2010 | 136 | 26 |
| 2009 | 28.3 | 55 |
| 2008 | 23.4 | 72 |
| 2007 | 23 | 71 |
| 2006 | 18.7 | 72 |
| 2005 | 11.6 | 71 |
| 2004 | 11.2 | 60 |
| 2003 | 9.1 | 62 |
| 2002 | 11 | 50 |
| 2001 | 9.4 | 51 |
| 2000 | 8.5 | 53 |
| 1999 | 8.1 | 53 |
| 1998 | 3.5 | 74 |
| 1997 | 5.5 | 58 |
| 1996 | 2.3 | 71 |
| 1995 | 2.4 | 62 |
| 1994 | 0.8 | 84 |
| 1993 | 0.8 | 80 |
| 1992 | 1.1 | 62 |
| 1991 | 0.8 | 64 |
| 1990 | 1.3 | 55 |
| 1989 | 0.7 | 55 |
| 1988 | 0.6 | 56 |
| 1987 | 0.5 | 57 |
| 1986 | 0.5 | 50 |