69% (1987)

63% (1985)

61% (1986)

64% (1987)

70% (1988)

57% (1989)

55% (1984)

46% (1987)

56% (1986)

68% (1989)

54% (1990)

53% (1986)

66% (1982)

70% (1985)

48% (1986)

54% (1981)

62% (1985)

52% (1981)

58% (1987)

62% (1986)