Year	constant 2015 US$
1960	341130000
1961	259310000
1962	199420000
1963	244100000
1964	205580000
1965	182250000
1966	144650000
1967	130500000
1968	144020000
1969	140140000
1970	172890000
1971	129210000
1972	115720000
1973	169800000
1974	181050000
1975	233190000
1976	302280000
1977	399440000
1978	243630000
1979	199070000
1980	155420000
1981	245100000
1982	142090000
1983	162930000
1984	70800000
1985	127460000
1986	81380000
1987	70440000
1988	68030000
1989	58970000
1990	77170000
1991	311820000
1992	544440000
1993	404680000
1994	552340000
1995	639890000
1996	659020000
1997	704610000
1998	860340000
1999	1158370000
2000	859270000
2001	1120610000
2002	843210000
2003	1100930000
2004	1095900000