63% (1964)

51% (1988)

51% (1977)

55% (1980)

49% (1990)

62% (1972)

45% (1989)

36% (1988)

45% (1988)

49% (1978)

51% (1990)

53% (1967)

56% (1969)

50% (1987)

55% (1980)

64% (1970)

58% (1977)

59% (1964)

52% (1972)

54% (1979)