48% (1976)

46% (1980)

54% (1985)

46% (1962)

53% (1980)

38% (1972)

45% (1974)

57% (1973)

46% (1977)

50% (1976)

52% (1976)

55% (1984)

59% (1987)

47% (1960)

47% (1989)

47% (1975)

42% (1962)

52% (1982)

43% (1961)

33% (1978)