52% (1985)

44% (1983)

43% (1982)

54% (1985)

55% (1988)

40% (1988)

52% (1986)

56% (1971)

50% (1981)

44% (1988)

46% (1972)

55% (1987)

67% (1984)

63% (1979)

49% (1971)

56% (1986)

57% (1988)

52% (1987)

48% (1983)

49% (1974)