56% (1977)

41% (1997)

39% (1980)

61% (1975)

70% (1976)

54% (1973)

61% (1974)

62% (1976)

52% (1970)

20% (1989)

53% (1982)

45% (1970)

53% (1977)

45% (1963)

10% (1973)

58% (1969)

0% (1976)

30% (1990)

45% (1972)

35% (1985)