72% (1989)

58% (1976)

42% (1972)

51% (1978)

50% (1973)

39% (1977)

40% (1978)

48% (1980)

42% (1975)

50% (1973)

45% (1983)

52% (1980)

54% (1972)

55% (1972)

46% (1983)

40% (1990)

62% (1970)

50% (1975)

50% (1973)

62% (1970)