52% (1974)

72% (1981)

51% (1979)

62% (1977)

67% (1984)

46% (1955)

46% (1985)

42% (1980)

70% (1959)

41% (1979)

80% (1969)

64% (1982)

60% (1969)

42% (1988)

42% (1969)

49% (1970)

47% (1990)

66% (1987)

55% (1968)

56% (1984)