70% (1977)

64% (1973)

71% (1969)

66% (1970)

59% (1972)

50% (1976)

58% (1975)

45% (1974)

61% (1968)

55% (1969)

58% (1969)

48% (1970)

53% (1971)

49% (1975)

53% (1969)

50% (1969)

55% (1972)

66% (1976)

59% (1972)

67% (1969)