55% (1975)

61% (1974)

72% (1977)

67% (1971)

55% (1976)

32% (1968)

49% (1970)

51% (1970)

57% (1971)

48% (1969)

72% (1944)

46% (1969)

62% (1974)

66% (1970)

61% (1972)

65% (1970)

57% (1972)

45% (1971)

66% (1976)

61% (1975)