64% (1970)

65% (1972)

71% (1972)

59% (1968)

55% (1969)

58% (1969)

57% (1972)

58% (1972)

59% (1971)

56% (1970)

51% (1970)

61% (1969)

47% (1971)

50% (1969)

45% (1973)

64% (1973)

54% (1972)

61% (1970)