51% (1953)

65% (1961)

72% (1959)

65% (1955)

65% (1968)

61% (1964)

65% (1965)

56% (2011)

59% (1972)

54% (1958)

55% (1964)

63% (1962)

62% (1963)

53% (1965)

50% (1969)

56% (1953)

62% (1974)

58% (1970)

58% (1971)

54% (1963)