45% (1981)

49% (1978)

51% (1977)

52% (1972)

51% (1988)

62% (1964)

53% (1975)

55% (1980)

46% (1989)

61% (1972)

49% (1990)

53% (1967)

56% (1984)

45% (1988)

57% (1964)

54% (1979)

56% (1969)

49% (1987)

54% (1980)

45% (1976)