55% (1992)

54% (1981)

53% (1988)

64% (1980)

52% (1972)

47% (1986)

60% (1971)

66% (1972)

55% (1987)

54% (1986)

64% (1970)

53% (1980)

62% (1972)

51% (1987)

62% (1985)

47% (1978)

57% (1983)

48% (1976)

25% (1982)

57% (1984)