45% (1971)

50% (1979)

43% (1961)

40% (1972)

37% (1977)

46% (1980)

33% (1983)

56% (1987)

39% (1972)

45% (1981)

32% (1978)

49% (1979)

37% (1986)

20% (1987)

45% (1986)

34% (1972)

30% (1963)

28% (1985)

29% (1964)

10% (1984)