51% (1981)

46% (1980)

51% (1978)

67% (1982)

48% (1974)

49% (1981)

53% (1980)

44% (1970)

50% (1981)

54% (1973)

66% (1973)

55% (1977)

41% (1974)

54% (1977)

40% (1983)

57% (1980)

34% (1974)

40% (1978)

57% (1972)

24% (1976)