Year	current US$
1960	1.8717867549112088
1961	1.6161105664464759
1962	0.5778772741805035
1963	1.5931479462320268
1964	0.07989499548938339
1965	1.1812446149142555
1966	0.6804595246729194
1967	0.711829831139849
1968	0.34712179568519475
1969	0.3338595620624317
1970	0.3561505346353625
1971	0.8973376793911256
1972	0.7008439482258634
1973	0.21454168856706055
1974	0.23527798697742475
1975	-0.25551371384590504
1976	0.5931828390343514
1977	0.45160022105347214
1978	0.5034815007247071
1979	2.415968486401221
1980	2.1508562626301675
1981	1.8366324145857293
1982	1.5063158568408435
1983	1.6426259065258255
1984	2.54728690787158
1985	3.7535280125795056
1986	3.343228344740705
1987	3.4745989408921063
1988	3.92707377593818
1989	7.1436106594711415
1990	6.689455666125357
1991	6.270862255706571
1992	-6.723558313938454
1993	5.129639121803711
1994	4.452066282140935
1995	2.880070099939296
1996	2.0511226492525987