59% (1971)

65% (1972)

47% (1971)

71% (1972)

58% (1969)

54% (1972)

45% (1973)

61% (1969)

51% (1970)

64% (1970)

57% (1972)

55% (1969)

56% (1970)

64% (1973)

50% (1969)

59% (1968)

58% (1972)

61% (1970)