57% (1967)

57% (1987)

52% (1987)

53% (1975)

41% (1985)

52% (1985)

62% (1983)

40% (1981)

44% (1987)

52% (1986)

35% (1984)

15% (1988)

40% (1983)

54% (1982)

23% (1985)

20% (1985)

30% (1987)

40% (1987)

45% (1988)