Year	constant 2015 US$
1964	90000
1965	400000
1966	440000
1967	450000
1968	310000
1969	80000
1970	70000
1972	60000
1974	150000
1975	80000
1976	130000
1977	270000
1978	440000
1979	360000
1980	600000
1981	470000
1982	160000
1983	160000
1984	190000
1985	2710000
1986	180000
1987	400000
1988	60000
1989	170000
1990	55820000
1991	-6290000
1992	-5950000
1993	-5840000
1994	-14520000
1995	-2070000
1996	-4270000
1997	-9930000
1998	770000
1999	110000
2000	80000
2001	30000
2002	20000
2003	40000
2004	100000