49% (1988)

57% (1986)

56% (1975)

67% (1984)

66% (1979)

52% (1987)

57% (1985)

59% (1987)

51% (1981)

50% (1971)

36% (1978)

40% (1978)

52% (1985)

64% (1977)

50% (1977)

50% (1985)

57% (1972)

56% (1976)

44% (1982)

58% (1979)