Year	Percent
1961	9.7876
1962	-0.82403
1963	3.29617
1964	13.10343
1965	12.89492
1966	-3.20637
1967	-0.32441
1968	3.39738
1969	6.52238
1970	0.68892
1971	1.84376
1972	11.99021
1973	11.61333
1974	13.07142
1975	16.87862
1976	14.73132
1977	9.79471
1978	14.63675
1979	13.04844
1980	100.90318
1981	20.12602
1982	26.83059
1983	32.00536
1984	71.67052
1985	29.60897
1986	33.52682
1987	32.65477
1988	69.84737
1989	97.41667
1990	215.4668