Year	US Dollars
1970	2337074000
1971	2635938000
1972	2964724000
1973	3326835000
1974	3515016000
1975	3934673000
1976	4123792000
1977	5232471000
1978	5286645000
1979	6056967000
1980	7135606000
1981	8925378000
1982	10519982000
1983	11639495000
1984	12274127000
1985	14474612000
1986	15583215000
1987	17237209000
1988	17214281000
1989	17075302000
1990	17404181000
1991	17371252000
1992	17451116000
1993	19107295000
1994	22097956000
1995	25203862000
1996	29057066000
1997	32139648000
1998	33283764000
1999	34775688000
2000	34272265000
2001	36568828000
2002	33534031000
2003	37273762000
2004	38190545000
2005	37465247000
2006	38310599000
2007	43964490000
2008	46688341000
2009	53330961000
2010	64096821000
2011	73813023000
2012	76781503000
2013	89720423000
2014	101375795000
2015	110875397000
2016	120282048000