58% (1980)

56% (1988)

51% (1971)

36% (1978)

50% (1981)

56% (1971)

46% (1972)

67% (1984)

55% (1976)

52% (1987)

59% (1987)

53% (1982)

41% (1982)

40% (1988)

52% (1985)

43% (1982)

56% (1983)

58% (1986)

54% (1971)

49% (1974)