68% (1985)

66% (1980)

68% (1985)

73% (1987)

71% (1988)

60% (1986)

61% (1986)

69% (1987)

65% (1986)

63% (1992)

61% (1990)

68% (1990)

77% (1986)

51% (1991)

58% (1982)

65% (1990)

78% (1987)

68% (1984)

61% (1984)

64% (1989)