| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2015 | 88 | 33 |
| 2014 | 108.1 | 29 |
| 2013 | 94.9 | 32 |
| 2012 | 88.3 | 35 |
| 2011 | 71.5 | 43 |
| 2010 | 88 | 36 |
| 2009 | 11.3 | 83 |
| 2008 | 50.6 | 52 |
| 2007 | 141.9 | 31 |
| 2006 | 128.1 | 30 |
| 2005 | 109 | 25 |
| 2004 | 100 | 18 |
| 2003 | 42.6 | 28 |
| 2002 | 1 | 113 |
| 2001 | 11.8 | 45 |
| 2000 | -5.1 | 182 |
| 1999 | -9.9 | 184 |
| 1998 | 2.6 | 83 |
| 1997 | 2.3 | 82 |
| 1996 | 3 | 63 |
| 1995 | 4 | 53 |
| 1994 | 0.6 | 92 |
| 1993 | 4 | 50 |
| 1992 | 1.3 | 55 |
| 1991 | 0.3 | 82 |
| 1990 | -1.2 | 148 |
| 1989 | 0.4 | 67 |
| 1988 | 1.9 | 38 |
| 1987 | 0.5 | 59 |
| 1986 | 1.1 | 40 |