51% (1976)

50% (1978)

52% (1976)

60% (1983)

70% (1978)

57% (1976)

50% (1975)

50% (1976)

58% (1975)

47% (1975)

66% (1977)

45% (1977)

62% (1978)

70% (1981)

61% (1974)

59% (1978)

52% (1982)

49% (1975)

58% (1975)

56% (1975)