63% (1979)

59% (1976)

51% (1969)

43% (1964)

44% (1976)

40% (1979)

63% (1978)

62% (1970)

58% (1965)

48% (1958)

52% (1973)

63% (1974)

72% (1965)

56% (1974)

60% (1975)

56% (1977)

66% (1964)

42% (1959)

66% (1973)

52% (1977)