| 时间 | 值 （亿美元） | 世界排名 |
|---|---|---|
| 2016 | 49.5 | 70 |
| 2015 | 48.2 | 81 |
| 2014 | 46.8 | 82 |
| 2013 | 45.8 | 85 |
| 2012 | 45.1 | 87 |
| 2011 | 45 | 86 |
| 2010 | 43.6 | 87 |
| 2009 | 47.5 | 81 |
| 2008 | 53.2 | 75 |
| 2007 | 51.9 | 73 |
| 2006 | 50.2 | 72 |
| 2005 | 47.2 | 72 |
| 2004 | 45.9 | 71 |
| 2003 | 44.3 | 70 |
| 2002 | 42.4 | 69 |
| 2001 | 41 | 70 |
| 2000 | 38.9 | 70 |
| 1999 | 40.2 | 67 |
| 1998 | 40.3 | 67 |
| 1997 | 35.7 | 67 |
| 1996 | 34.5 | 67 |
| 1995 | 36.4 | 67 |