50% (1981)

46% (1980)

51% (1978)

52% (1981)

67% (1982)

47% (1974)

49% (1981)

37% (1978)

46% (1970)

54% (1973)

49% (1976)

37% (1974)

52% (1980)

52% (1977)

56% (1977)

55% (1973)

40% (1974)

46% (1988)

47% (1978)

45% (1978)