69% (1972)

56% (1974)

61% (1972)

60% (1981)

63% (1971)

61% (1967)

51% (1976)

61% (1973)

54% (1977)

63% (1973)

64% (1965)

60% (1965)

57% (1965)

62% (1974)

64% (1969)

66% (1974)

54% (1974)

54% (1970)

61% (1967)

44% (1966)