42% (1956)

45% (1968)

37% (1964)

45% (1968)

43% (1968)

62% (1961)

56% (1974)

29% (1962)

55% (1966)

32% (1958)

57% (1957)

52% (1966)

58% (1965)

50% (1979)

43% (1978)

52% (1976)

42% (1971)

44% (1969)

51% (1974)

59% (1968)