56% (1986)

57% (1985)

44% (1987)

45% (1983)

37% (1970)

54% (1973)

45% (1985)

61% (1968)

60% (1984)

39% (1984)

48% (1974)

63% (1971)

51% (1971)

37% (1988)

55% (1967)

69% (1969)

56% (1969)

49% (1969)

57% (1970)

18% (1971)