| 时间 |
值 （亿美元） |
世界排名 |
| 2016 |
5 |
74 |
| 2015 |
4.7 |
83 |
| 2014 |
5.1 |
83 |
| 2013 |
4.8 |
82 |
| 2012 |
4.4 |
82 |
| 2011 |
3.9 |
87 |
| 2010 |
3.3 |
92 |
| 2009 |
4.3 |
84 |
| 2008 |
5.1 |
86 |
| 2007 |
4.4 |
83 |
| 2006 |
3.2 |
87 |
| 2005 |
2.7 |
88 |
| 2004 |
2 |
91 |
| 2003 |
1.7 |
96 |
| 2002 |
1.2 |
96 |
| 2001 |
0.9 |
97 |
| 2000 |
0.8 |
99 |
| 1999 |
0.7 |
100 |
| 1998 |
0.6 |
102 |
| 1997 |
0.5 |
110 |
| 1996 |
0.4 |
112 |
| 1995 |
0.4 |
106 |