52% (1966)

50% (1968)

42% (1971)

42% (1956)

48% (1965)

47% (1976)

42% (1978)

53% (1967)

58% (1976)

56% (1971)

57% (1957)

35% (1974)

52% (1973)

58% (1963)

57% (1957)

65% (1975)

47% (1955)

52% (1967)

57% (1958)

50% (1964)