64% (1975)

40% (1987)

37% (1976)

62% (1980)

60% (1984)

73% (1987)

65% (1984)

57% (1975)

75% (1980)

80% (1979)

70% (1987)

50% (1979)

63% (1988)

73% (1984)

70% (1984)

70% (1984)

78% (1981)

73% (1985)

70% (1982)

70% (1978)