Year	US Dollars
1970	145249000
1971	152514000
1972	161629000
1973	199392000
1974	265056000
1975	349085000
1976	409700000
1977	628092000
1978	894938000
1979	1122625000
1980	1473261000
1981	1670739000
1982	1859905000
1983	2072976000
1984	2197167000
1985	2559363000
1986	3230705000
1987	4036579000
1988	3893078000
1989	3278511000
1990	3750335000
1991	3589291000
1992	3684278000
1993	3843449000
1994	3697802000
1995	3915938000
1996	3786093000
1997	3805576000
1998	4096781000
1999	4000850000
2000	3653475000
2001	3700968000
2002	4118759000
2003	4397900000
2004	3940276000
2005	3861744000
2006	1936524000
2007	2585778000
2008	2850926000
2009	3720889000
2010	3909477000
2011	4325490000
2012	4905679000
2013	5225562000
2014	5619669000
2015	5893172000
2016	6637541000