62% (1966)

61% (1963)

63% (1964)

37% (1970)

56% (1975)

44% (1967)

71% (1965)

55% (1967)

54% (1961)

42% (1958)

58% (1977)

50% (1962)

51% (1970)

64% (1976)

65% (1968)

61% (1965)

44% (1973)

60% (1966)

64% (1977)

47% (1968)