50% (1962)

54% (1959)

56% (1958)

58% (1964)

56% (1956)

62% (1960)

53% (1962)

55% (1957)

56% (1965)

59% (1965)

61% (1964)

64% (1967)

50% (1957)

51% (1960)

53% (1963)

50% (1957)

50% (1964)

52% (1957)

55% (1958)

50% (1959)