61% (1981)

58% (1975)

52% (1982)

63% (1977)

68% (1975)

56% (1975)

60% (1981)

70% (1981)

53% (1975)

65% (1979)

53% (1982)

40% (1978)

60% (1975)

52% (1976)

56% (1977)

49% (1976)

55% (1975)

48% (1983)

50% (1976)

51% (1983)