56% (1975)

68% (1971)

59% (1978)

55% (1987)

62% (1970)

41% (1976)

50% (1978)

52% (1979)

46% (1978)

64% (1971)

58% (1969)

47% (1977)

66% (1977)

61% (1970)

56% (1971)

58% (1970)

75% (1971)

54% (1971)

50% (1971)

55% (1988)