71% (1988)

66% (1980)

69% (1985)

60% (1986)

68% (1985)

61% (1986)

65% (1986)

77% (1986)

73% (1987)

61% (1990)

69% (1987)

63% (1992)

58% (1982)

57% (1990)

51% (1991)

68% (1984)

64% (1989)

70% (1987)

61% (1984)

64% (1988)