54% (1974)

62% (1972)

50% (1973)

54% (1971)

57% (1976)

51% (1970)

45% (1974)

36% (1976)

68% (1975)

35% (1976)

58% (1978)

55% (1971)

66% (1974)

56% (1969)

54% (1970)

49% (1976)

59% (1975)

56% (1973)

53% (1970)

0% (1971)