Year	US Dollars
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	8885000
1979	12814000
1980	25763000
1981	38886000
1982	65069000
1983	77222000
1984	82808000
1985	83066000
1986	68686000
1987	72837000
1988	71361000
1989	66800000
1990	77967000
1991	81243000
1992	94899000
1993	112349000
1994	123524000
1995	154868000
1996	168203000
1997	171334000
1998	193600000
1999	219242000
2000	203022000
2001	233030000
2002	269845000
2003	292924000
2004	339687000
2005	362339000
2006	553704000
2007	771852000
2008	1147407000
2009	1383451000
2010	916603000
2011	881966000
2012	889126000
2013	898847000
2014	1060176000
2015	966461000
2016	1155159000