72% (1978)

71% (1979)

70% (1977)

59% (1975)

37% (1976)

60% (1982)

0% (1984)

0% (1984)

58% (1985)

64% (1979)

10% (1982)

60% (1982)

10% (1983)

10% (1983)

68% (1975)

0% (1986)

10% (1980)

0% (1981)

55% (1983)

0% (1986)