70% (1964)

75% (1978)

58% (1988)

58% (1990)

40% (1970)

0% (1984)

0% (1978)

55% (1981)

0% (1976)

75% (1987)

57% (1979)

50% (1979)

60% (1981)

80% (1981)

40% (1985)

0% (1975)

51% (1982)

0% (1977)

40% (1979)

0% (1989)