| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 81.7 | 25 |
| 2015 | 76.4 | 28 |
| 2014 | 69.3 | 29 |
| 2013 | 83.8 | 26 |
| 2012 | 65.3 | 29 |
| 2011 | 58.4 | 31 |
| 2010 | 46.6 | 35 |
| 2009 | 33 | 46 |
| 2008 | 32.3 | 45 |
| 2007 | 33.5 | 42 |
| 2006 | 26.1 | 44 |
| 2005 | 21.5 | 44 |
| 2004 | 24.3 | 41 |
| 2003 | 21.3 | 41 |
| 2002 | 13.7 | 45 |
| 2001 | 9.2 | 52 |
| 2000 | 11.3 | 48 |
| 1999 | 11.4 | 49 |
| 1998 | 9.7 | 53 |
| 1997 | 32.3 | 29 |
| 1996 | 28.7 | 32 |
| 1995 | 24.8 | 35 |
| 1994 | 22.4 | 33 |
| 1993 | 19.3 | 35 |
| 1992 | 18.9 | 36 |
| 1991 | 17 | 34 |
| 1990 | 16.1 | 38 |
| 1989 | 14.1 | 38 |
| 1988 | 13.6 | 36 |
| 1987 | 13.5 | 34 |
| 1986 | 17.3 | 28 |