53% (1952)

58% (1972)

60% (1966)

57% (1972)

52% (1967)

48% (1971)

68% (1954)

63% (1997)

45% (1971)

59% (1976)

65% (1969)

63% (1969)

62% (1976)

52% (1967)

67% (1976)

74% (1951)

68% (1968)

50% (1964)

63% (1979)

71% (1976)