58% (1975)

35% (1968)

54% (1970)

50% (1962)

68% (1974)

41% (1971)

51% (1965)

42% (1990)

72% (1977)

30% (1980)

54% (1987)

75% (1981)

45% (1991)

58% (1988)

30% (1986)

57% (1992)

40% (1991)

51% (1969)

47% (1996)

48% (1970)