51% (1971)

42% (1973)

55% (1977)

42% (1986)

25% (1981)

37% (1979)

57% (1976)

43% (1971)

49% (1971)

30% (1983)

47% (1974)

60% (1973)

10% (1986)

50% (1975)

62% (1986)

20% (1973)

54% (1970)

20% (1987)

0% (1987)