Year	US Dollars
1970	242871000
1971	295917000
1972	354333000
1973	498245000
1974	675465000
1975	871396000
1976	962315000
1977	1355890000
1978	1525327000
1979	1615170000
1980	2273188000
1981	2561917000
1982	3037460000
1983	4202528000
1984	4912584000
1985	5880202000
1986	6895951000
1987	8091575000
1988	8811783000
1989	9875554000
1990	10976875000
1991	11128236000
1992	11407267000
1993	11657297000
1994	12406061000
1995	10591396000
1996	6174326000
1997	6321398000
1998	6379426000
1999	6409337000
2000	6822425000
2001	6386367000
2002	6438633000
2003	6851623000
2004	5089954000
2005	5000022000
2006	4182738000
2007	4106280000
2008	4711433000
2009	5892377000
2010	6999963000
2011	7945763000
2012	5534011000
2013	9712384000
2014	10145469000
2015	10546824000
2016	10990903000