71% (1972)

59% (1968)

64% (1972)

58% (1969)

64% (1970)

54% (1969)

57% (1972)

56% (1970)

59% (1972)

61% (1969)

59% (1971)

47% (1971)

54% (1972)

64% (1973)

51% (1970)

63% (1970)

50% (1969)

45% (1973)