Year	constant 2015 US$
1960	3910000
1961	4990000
1962	3830000
1963	3430000
1964	4540000
1965	120000
1966	9950000
1967	11910000
1968	9400000
1969	6780000
1970	31040000
1971	30830000
1972	23370000
1973	3410000
1974	2360000
1975	14030000
1976	3540000
1977	107230000
1978	4270000
1979	15090000
1980	8860000
1981	120000
1982	10910000
1983	10060000
1984	8150000
1985	9600000
1986	65750000
1987	180690000
1988	-18760000
1989	-9940000
1990	4610000
1991	-11280000
1992	-11770000
1993	-12730000
1994	-9910000
1995	5090000