57% (1971)

54% (1975)

45% (1971)

36% (1975)

53% (1978)

54% (1970)

52% (1973)

50% (1974)

20% (1975)

55% (1974)

40% (1970)

64% (1975)

20% (1972)

54% (1967)

39% (1974)

30% (1969)

40% (1971)

10% (1973)

40% (1971)

45% (1973)