78% (1981)

54% (1985)

81% (1981)

45% (1973)

70% (1975)

57% (1981)

70% (1986)

63% (1977)

70% (1978)

57% (1975)

60% (1984)

73% (1987)

72% (1978)

58% (1973)

70% (1979)

70% (1984)

70% (1981)

70% (1987)

70% (1981)

63% (1989)