55% (1959)

47% (1972)

45% (1980)

40% (1972)

55% (1964)

60% (1970)

48% (1971)

64% (1971)

80% (1971)

45% (1968)

30% (1957)

40% (1969)

48% (1968)

60% (1974)

70% (1972)

60% (1963)

40% (1971)

40% (1970)

48% (1967)

48% (1968)