60% (1972)

72% (1964)

54% (1979)

60% (1969)

64% (1981)

53% (1980)

59% (1979)

56% (1972)

58% (1981)

65% (1986)

58% (1983)

59% (1984)

56% (1981)

49% (1968)

51% (1968)

55% (1984)

54% (1982)

48% (1979)

50% (1968)

56% (1985)