| 时间 |
值 （亿美元） |
世界排名 |
| 2016 |
34.2 |
135 |
| 2015 |
30.7 |
160 |
| 2014 |
25.3 |
162 |
| 2013 |
22.7 |
166 |
| 2012 |
21.7 |
168 |
| 2011 |
23 |
172 |
| 2010 |
20.1 |
170 |
| 2009 |
19.2 |
169 |
| 2008 |
22.2 |
165 |
| 2007 |
15.8 |
169 |
| 2006 |
17.4 |
163 |
| 1994 |
3.6 |
159 |
| 1993 |
3.6 |
154 |
| 1992 |
3 |
157 |
| 1991 |
2.6 |
156 |
| 1990 |
2.1 |
155 |
| 1989 |
1.8 |
138 |
| 1988 |
1.6 |
134 |
| 1987 |
1.2 |
135 |
| 1986 |
1.3 |
135 |