| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 82.2 | 58 |
| 2015 | 76.9 | 68 |
| 2014 | 68 | 71 |
| 2013 | 66.9 | 74 |
| 2012 | 63.1 | 76 |
| 2011 | 59 | 76 |
| 2010 | 56.7 | 79 |
| 2009 | 54.7 | 76 |
| 2008 | 50.3 | 77 |
| 2007 | 46.4 | 77 |
| 2006 | 42.9 | 76 |
| 2005 | 43.7 | 75 |
| 2004 | 44.1 | 73 |
| 2003 | 43.8 | 71 |
| 2002 | 41.4 | 71 |
| 2001 | 40.7 | 71 |
| 2000 | 39.6 | 69 |
| 1999 | 40.5 | 66 |
| 1998 | 41.5 | 66 |
| 1997 | 40.1 | 66 |
| 1996 | 40.2 | 66 |
| 1995 | 39.2 | 66 |
| 1994 | 35.7 | 62 |
| 1993 | 27.6 | 64 |
| 1992 | 25.6 | 64 |
| 1991 | 23.5 | 64 |
| 1990 | 22.2 | 63 |
| 1989 | 21.2 | 53 |
| 1988 | 20.9 | 53 |
| 1987 | 20.6 | 55 |
| 1986 | 19.9 | 54 |