67% (1976)

67% (1979)

53% (1978)

60% (1974)

73% (1983)

48% (1980)

55% (1982)

42% (1981)

46% (1973)

58% (1989)

46% (1981)

45% (1986)

62% (1973)

62% (1978)

55% (1971)

52% (1982)

43% (1977)

62% (1988)

37% (1993)

43% (1989)