Year	US Dollars
1970	17359000
1971	33200000
1972	74755000
1973	114918000
1974	134057000
1975	147981000
1976	166351000
1977	185565000
1978	125538000
1979	130020000
1980	135630000
1981	159543000
1982	204805000
1983	228124000
1984	266914000
1985	345664000
1986	407034000
1987	543405000
1988	532597000
1989	549843000
1990	552922000
1991	612559000
1992	606350000
1993	663983000
1994	700390000
1995	717156000
1996	626529000
1997	574728000
1998	532171000
1999	510194000
2000	452434000
2001	400351000
2002	491349000
2003	514126000
2004	515798000
2005	460535000
2006	364732000
2007	425191000
2008	448509000
2009	1643302000
2010	1806940000
2011	2395189000
2012	2517054000
2013	2379268000
2014	2545565000
2015	2221726000
2016	2100343000