Year	US Dollars
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	1041777000
1994	1103614000
1995	1277119000
1996	1818416000
1997	1233574000
1998	1489950000
1999	1436805000
2000	1479938000
2001	1498001000
2002	1685420000
2003	1889304000
2004	2829110000
2005	2981489000
2006	3296984000
2007	4174060000
2008	4337476000
2009	5246915000
2010	5159225000
2011	6131376000
2012	6469413000
2013	6736814000
2014	7232873000
2015	6766730000
2016	7382761000