72% (1989)

78% (1988)

72% (1985)

78% (1985)

65% (1983)

65% (1989)

65% (1987)

69% (1987)

70% (1988)

61% (1986)

63% (1989)

58% (1986)

55% (1987)

64% (1985)

52% (1986)

42% (1988)

66% (1985)

53% (1983)

52% (1985)

59% (1982)