| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 26.4 | 49 |
| 2015 | 36.2 | 41 |
| 2014 | 68.5 | 31 |
| 2013 | 60.9 | 32 |
| 2012 | 41.5 | 43 |
| 2011 | 36.4 | 46 |
| 2010 | 35 | 44 |
| 2009 | 33.1 | 45 |
| 2008 | 31.6 | 47 |
| 2007 | 20.3 | 51 |
| 2006 | 19.7 | 49 |
| 2005 | 13.7 | 55 |
| 2004 | 8.2 | 61 |
| 2003 | 6.7 | 66 |
| 2002 | 4.4 | 72 |
| 2001 | 4 | 68 |
| 2000 | 5.8 | 63 |
| 1999 | 10.7 | 50 |
| 1998 | 1.7 | 83 |
| 1997 | 4.6 | 66 |
| 1996 | 1.8 | 76 |
| 1995 | 2.4 | 72 |
| 1994 | 2.3 | 71 |
| 1993 | 9.3 | 49 |
| 1992 | 4.4 | 56 |
| 1991 | 8.6 | 49 |
| 1990 | 17.5 | 36 |
| 1989 | 19.5 | 29 |
| 1988 | 14.7 | 35 |
| 1987 | 14.9 | 32 |
| 1986 | 11.6 | 34 |