78% (1976)

63% (1966)

54% (1968)

81% (1967)

62% (1964)

67% (1977)

70% (1969)

67% (1970)

79% (1973)

40% (1974)

45% (1969)

49% (1967)

63% (1966)

49% (1965)

53% (1963)

53% (1968)

53% (1965)

57% (1974)

50% (1970)

62% (1975)