55% (1992)

52% (1988)

54% (1981)

66% (1972)

64% (1980)

57% (1983)

53% (1980)

55% (1987)

54% (1986)

66% (1984)

62% (1972)

58% (1981)

58% (1975)

32% (1984)

47% (1986)

51% (1987)

54% (1984)

52% (1972)

64% (1970)

52% (1985)