39% (1978)

46% (1980)

55% (1977)

44% (1973)

38% (1983)

31% (1975)

37% (1977)

32% (1981)

31% (1982)

46% (1975)

41% (1980)

44% (1980)

52% (1976)

42% (1986)

36% (1983)

38% (1978)

51% (1977)

54% (1979)

47% (1964)

25% (1974)