Year	US Dollars
1970	61400000
1971	111055000
1972	119390000
1973	141785000
1974	192928000
1975	204956000
1976	233372000
1977	289672000
1978	346963000
1979	420272000
1980	484855000
1981	603585000
1982	648423000
1983	648738000
1984	620423000
1985	712219000
1986	872668000
1987	1036090000
1988	1036490000
1989	1089993000
1990	1196555000
1991	1271198000
1992	1390146000
1993	1556462000
1994	1557983000
1995	1249602000
1996	1241842000
1997	1200051000
1998	1314137000
1999	1319225000
2000	1248360000
2001	1256747000
2002	1408407000
2003	1575773000
2004	1683351000
2005	1804617000
2006	1528634000
2007	551068000
2008	633809000
2009	856855000
2010	931128000
2011	1050425000
2012	1127198000
2013	1395487000
2014	1237664000
2015	1378425000
2016	1472407000