Year	US Dollars
1960	21.5379
1961	39.71333
1962	19.32671
1963	-0.43867
1964	21.84435
1965	44.33291
1966	73.12988
1967	108.59584
1968	35.14252
1969	52.74826
1970	99.30673
1971	141.12084
1972	153.35066
1973	226.7944
1974	238.30951
1975	108.31873
1976	104.75108
1977	157.03849
1978	123.92487
1979	228.17808
1980	388.04203
1981	257.46903
1982	108.09687
1983	117.48398
1984	380.71419
1985	1008.5792
1986	730.37254
1987	514.99719
1988	578.2143
1989	16.25253
1990	20.50005
1991	95.22751
1992	116.53368
1993	-0.36876
1994	20.8929
1995	7.66088
1996	-8.73013
1997	13.42331
1998	7.96063
1999	1.08323