51% (1978)

44% (1970)

52% (1981)

48% (1974)

57% (1972)

67% (1982)

45% (1983)

47% (1984)

35% (1978)

56% (1973)

46% (1978)

55% (1977)

66% (1973)

52% (1980)

57% (1980)

45% (1980)

30% (1976)

53% (1985)

50% (1981)

34% (1974)