44% (1974)

60% (1980)

46% (1975)

50% (1983)

46% (1980)

36% (1973)

53% (1973)

48% (1985)

37% (1985)

34% (1969)

53% (1982)

46% (1977)

55% (1984)

48% (1976)

53% (1985)

53% (1976)

39% (1978)

46% (1986)

46% (1989)

58% (1987)