Year	US Dollars
1960	1.87179
1961	1.61611
1962	0.57788
1963	1.59315
1964	0.07989
1965	1.18124
1966	0.68046
1967	0.71183
1968	0.34712
1969	0.33386
1970	0.35615
1971	0.89734
1972	0.70084
1973	0.21454
1974	0.23528
1975	-0.25551
1976	0.59318
1977	0.4516
1978	0.50348
1979	2.41597
1980	2.15086
1981	1.83663
1982	1.50632
1983	1.64263
1984	2.54729
1985	3.75353
1986	3.34323
1987	3.4746
1988	3.92707
1989	7.14361
1990	6.68946
1991	6.27086
1992	-6.72356
1993	5.12964
1994	4.45207
1995	2.88007
1996	2.05112