Year	US Dollars
1970	26314000
1971	38922000
1972	55904000
1973	105096000
1974	167766000
1975	188224000
1976	407018000
1977	522569000
1978	682624000
1979	716478000
1980	839481000
1981	964380000
1982	1136811000
1983	1277250000
1984	1320993000
1985	1454647000
1986	1746214000
1987	2028383000
1988	2051136000
1989	1971950000
1990	2113533000
1991	2205554000
1992	2104794000
1993	2173839000
1994	2259621000
1995	2395727000
1996	2456556000
1997	2493427000
1998	2390770000
1999	2545605000
2000	2390391000
2001	2297436000
2002	2279009000
2003	2358115000
2004	2338403000
2005	2321444000
2006	1598821000
2007	1719436000
2008	2000565000
2009	2288781000
2010	2683433000
2011	2814577000
2012	3305185000
2013	3522499000
2014	3520506000
2015	3775705000
2016	3833466000