Year	US Dollars
1970	3801000
1971	9158000
1972	12307000
1973	20104000
1974	27554000
1975	34016000
1976	49576000
1977	100530000
1978	112580000
1979	146348000
1980	204542000
1981	278508000
1982	352867000
1983	452493000
1984	470357000
1985	589873000
1986	743900000
1987	985967000
1988	1165408000
1989	1355914000
1990	1626888000
1991	1765334000
1992	1798258000
1993	2003259000
1994	2320468000
1995	2409946000
1996	2398114000
1997	2413516000
1998	2670154000
1999	3030863000
2000	2877903000
2001	2743437000
2002	3001370000
2003	3216534000
2004	3369369000
2005	3191118000
2006	3404460000
2007	3615024000
2008	3697621000
2009	3778430000
2010	3788739000
2011	3828257000
2012	4221259000
2013	4013314000
2014	4166023000
2015	4138852000
2016	4251270000