78% (1967)

70% (1976)

68% (1978)

60% (1977)

57% (1978)

72% (1975)

56% (1964)

68% (1962)

47% (1973)

49% (1973)

66% (1956)

0% (1964)

50% (1958)

0% (1980)

65% (1976)

59% (1970)

30% (1957)

40% (1960)

53% (1955)

70% (1959)