71% (1985)

67% (1986)

52% (1991)

72% (1986)

69% (1989)

70% (1990)

74% (1990)

67% (1988)

62% (1990)

61% (1991)

62% (1988)

48% (1984)

66% (1987)

65% (1988)

73% (1987)

65% (1992)

66% (1986)

69% (1987)

74% (1986)

64% (1986)