58% (1977)

52% (1973)

52% (1976)

52% (1980)

46% (1978)

58% (1980)

55% (1980)

47% (1976)

58% (1977)

44% (1977)

45% (1978)

48% (1977)

50% (1977)

44% (1974)

58% (1976)

60% (1975)

48% (1977)

59% (1974)

0% (1940)

50% (1956)