| 时间 |
值 （亿美元） |
世界排名 |
| 2015 |
8 |
117 |
| 2014 |
9 |
123 |
| 2013 |
10 |
119 |
| 2012 |
10 |
122 |
| 2011 |
8 |
121 |
| 2010 |
6 |
122 |
| 2009 |
6 |
121 |
| 2008 |
8 |
116 |
| 2007 |
7 |
118 |
| 2006 |
4 |
126 |
| 2005 |
2 |
132 |
| 2004 |
2 |
126 |
| 2003 |
1 |
132 |
| 2002 |
1 |
133 |
| 2001 |
1 |
134 |
| 2000 |
1 |
135 |
| 1999 |
1 |
133 |
| 1998 |
1 |
133 |
| 1997 |
0 |
135 |
| 1996 |
0 |
138 |
| 1995 |
0 |
127 |
| 1994 |
0 |
128 |
| 1993 |
0 |
141 |