69% (1987)

73% (1988)

59% (1978)

66% (1988)

63% (1986)

65% (1988)

62% (1975)

62% (1985)

60% (1985)

59% (1987)

53% (1981)

65% (1990)

57% (1972)

61% (1984)

63% (1987)

59% (1984)

61% (1985)

52% (1982)

48% (1983)

56% (1984)