64% (1975)

73% (1987)

62% (1980)

70% (1978)

73% (1978)

40% (1987)

70% (1979)

78% (1981)

80% (1979)

70% (1987)

63% (1988)

70% (1977)

68% (1975)

75% (1980)

72% (1978)

70% (1978)

63% (1987)

65% (1976)

63% (1974)

70% (1981)