71% (1971)

35% (1968)

78% (1973)

63% (1988)

64% (1980)

78% (1980)

82% (1985)

77% (1985)

86% (1979)

60% (1980)

73% (1969)

80% (1980)

70% (1978)

64% (1983)

90% (1986)

67% (1982)

80% (1979)

77% (1990)

70% (1969)

63% (1990)