Year	Percent
1960-01-01	1.1263800000000000
1961-01-01	0.9176610000000001
1962-01-01	0.4780420000000000
1963-01-01	0.5988330000000000
1964-01-01	0.9300879999999999
1965-01-01	1.9162099999999997
1966-01-01	2.8215500000000000
1967-01-01	1.8993300000000000
1968-01-01	0.9739430000000000
1969-01-01	2.5204100000000000
1970-01-01	3.1898000000000000
1971-01-01	2.7208799999999997
1972-01-01	3.8455300000000000
1973-01-01	5.8405500000000000
1974-01-01	7.1834700000000000
1975-01-01	8.4243800000000010
1976-01-01	8.0265000000000000
1977-01-01	9.4337600000000010
1978-01-01	11.2499000000000000
1979-01-01	10.8098000000000000
1980-01-01	10.2094000000000000
1981-01-01	10.3518000000000000
1982-01-01	13.4998000000000000
1983-01-01	15.3691000000000000
1984-01-01	11.5871000000000000
1985-01-01	9.7616800000000000
1986-01-01	9.5624800000000000
1987-01-01	5.9284300000000005
1988-01-01	5.4697400000000000
1989-01-01	6.1624300000000005
1990-01-01	5.4203400000000000
1991-01-01	4.0091700000000000
1992-01-01	2.7612700000000000
1993-01-01	1.4033900000000000
1994-01-01	0.3683670000000000
1995-01-01	0.3142110000000000
1996-01-01	0.4123890000000000
1997-01-01	0.1516850000000000
1998-01-01	0.0000000000001200