63% (1984)

62% (1983)

48% (1982)

63% (1984)

70% (1986)

37% (1979)

78% (1981)

57% (1981)

65% (1984)

37% (1976)

45% (1973)

70% (1981)

73% (1985)

72% (1987)

75% (1980)

60% (1989)

70% (1987)

50% (1979)

70% (1984)

48% (1979)