62% (1980)

65% (1976)

67% (1984)

45% (1973)

57% (1981)

54% (1985)

67% (1989)

63% (1987)

65% (1982)

63% (1984)

37% (1976)

60% (1988)

55% (1977)

70% (1986)

67% (1980)

60% (1988)

70% (1979)

73% (1983)

60% (1977)

70% (1982)