56% (1977)

41% (1997)

52% (1970)

54% (1973)

61% (1975)

39% (1980)

54% (1977)

53% (1982)

70% (1976)

58% (1969)

20% (1989)

61% (1974)

45% (1970)

62% (1976)

30% (1990)

45% (1963)

0% (1976)

67% (1970)

37% (1973)

45% (1972)