Year	current US$
1964	6800000
1965	5500000
1966	4600000
1967	4400000
1968	5400000
1969	6444000
1970	4500000
1971	6300000
1972	5100000
1973	6545000
1974	12709000
1975	7208000
1976	6859000
1977	15254000
1978	10134000
1979	18762000
1980	17809000
1981	12195000
1982	14308000
1983	17392000
1984	21029000
1985	27263000
1986	10487000
1987	11079000
1988	15852000
1989	13685188.110000001
1990	12461711.99
1991	8160273.319
1992	5803287.005
1993	6434830.264
1994	3976921.302
1995	60900149.220000006
1996	64754054.78
1997	64685190.82
1998	73972940.17999999
1999	64791892.27
2000	48507520
2001	61747031
2002	70286549
2003	85922154
2004	83932974
2005	233556890
2006	63964649
2007	97113098
2008	72478819
2009	48012367
2010	60454664
2011	55153827
2012	58923440
2013	48450722
2014	53810264
2015	61046933
2016	64026461
2017	40479601
2018	40247222
2019	43770147
2020	50009722