64% (1975)

73% (1978)

73% (1987)

63% (1987)

70% (1978)

70% (1986)

63% (1984)

78% (1981)

65% (1988)

70% (1975)

65% (1976)

73% (1983)

70% (1987)

70% (1978)

70% (1977)

70% (1979)

37% (1976)

70% (1984)

40% (1987)

54% (1985)