47% (1972)

62% (1976)

56% (1980)

60% (1982)

62% (1982)

65% (1981)

60% (1981)

54% (1976)

60% (1975)

48% (1973)

50% (1979)

60% (1974)

55% (1979)

68% (1983)

25% (1979)

80% (1971)

65% (1981)

60% (1979)

0% (1969)

0% (1975)