Year	Percent
1960	60.17517
1961	74.66323
1962	59.62583
1963	34.99589
1964	32.20644
1965	47.87181
1966	27.05515
1967	24.03572
1968	14.45224
1969	14.71913
1970	11.58658
1971	13.119
1972	15.66219
1973	7.81295
1974	3.95589
1975	3.98246
1976	2.61549
1977	2.04914
1978	0.91623
1979	0.53357
1980	0.62326
1981	1.40859
1982	0.13486
1983	0.02681
1984	-0.1171
1985	-0.02698
1986	-0.04611
1987	0.02211
1988	0.01335
1989	0.05699
1990	0.04665
1991	0.03992
1992	-0.00225
1993	-0.02375
1994	-0.06398
1995	0.02583
1996	-0.0619
1997	-0.07535
1998	-0.0473
1999	-0.03571