66% (1988)

69% (1987)

62% (1985)

73% (1989)

61% (1984)

51% (1971)

63% (1989)

60% (1985)

62% (1986)

60% (1978)

61% (1975)

65% (1990)

64% (1988)

57% (1972)

63% (1987)

63% (1984)

42% (1978)

62% (1985)

67% (1985)

56% (1986)