57% (1975)

46% (1977)

50% (1974)

60% (1975)

61% (1968)

40% (1978)

0% (1982)

65% (1984)

60% (1980)

68% (1978)

60% (1986)

57% (1973)

63% (1981)

63% (1976)

64% (1980)

52% (1980)

78% (1973)

63% (1972)

70% (1968)

68% (1984)