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	15515000
1982	17123000
1983	18910000
1984	20295000
1985	23113000
1986	31803000
1987	46730000
1988	57461000
1989	65675000
1990	79177000
1991	82342000
1992	97983000
1993	100853000
1994	113598000
1995	128274000
1996	141574000
1997	152939000
1998	183325000
1999	185311000
2000	222227000
2001	252570000
2002	286807000
2003	331848000
2004	355539000
2005	415674000
2006	369061000
2007	474858000
2008	832194000
2009	433129000
2010	579623000
2011	451198000
2012	429781000
2013	474018000
2014	529296000
2015	533526000
2016	551039000