50% (1981)

55% (1973)

72% (1977)

53% (1970)

44% (1972)

57% (1971)

52% (1973)

50% (1977)

44% (1975)

46% (1972)

42% (1974)

45% (1974)

58% (1979)

49% (1981)

50% (1959)

45% (1980)

42% (1973)

34% (1960)

46% (1978)

43% (1973)