47% (1972)

62% (1976)

60% (1974)

56% (1980)

48% (1973)

55% (1979)

65% (1981)

65% (1981)

62% (1982)

60% (1982)

80% (1971)

60% (1981)

66% (1981)

57% (1975)

54% (1976)

68% (1983)

50% (1979)

25% (1979)

0% (1977)

60% (1979)