58% (1983)

60% (1982)

72% (1982)

66% (1984)

82% (1981)

64% (1986)

77% (1984)

59% (1983)

56% (1981)

49% (1985)

70% (1985)

64% (1982)

57% (1987)

42% (1988)

59% (1982)

63% (1984)

52% (1984)

57% (1984)

52% (1983)

67% (1987)