52% (1966)

54% (1977)

55% (1973)

65% (1959)

40% (1956)

47% (1979)

62% (1974)

60% (1975)

52% (1965)

59% (1963)

55% (1972)

56% (1958)

53% (1970)

50% (1960)

49% (1957)

62% (1962)

57% (1975)

49% (1965)

71% (1964)

48% (1969)