Year	US Dollars
1970	14970000
1971	13628000
1972	6895000
1973	7780000
1974	9438000
1975	19380000
1976	22364000
1977	47222000
1978	74680000
1979	136188000
1980	165720000
1981	178613000
1982	227433000
1983	307725000
1984	348005000
1985	455098000
1986	570431000
1987	769580000
1988	800692000
1989	888847000
1990	906937000
1991	963470000
1992	1026584000
1993	1065650000
1994	1127405000
1995	1161955000
1996	1130743000
1997	1068958000
1998	1121832000
1999	1153730000
2000	1125866000
2001	1093541000
2002	1232211000
2003	1348343000
2004	1357933000
2005	1287890000
2006	1371906000
2007	1409727000
2008	1390284000
2009	607228000
2010	620920000
2011	604411000
2012	667316000
2013	683609000
2014	690170000
2015	625980000
2016	632780000