51% (1977)

49% (1978)

63% (1964)

51% (1975)

55% (1980)

51% (1972)

45% (1973)

64% (1970)

45% (1981)

62% (1972)

60% (1971)

45% (1989)

44% (1988)

56% (1980)

54% (1967)

49% (1990)

54% (1968)

50% (1988)

60% (1964)

52% (1979)