63% (1975)

71% (1972)

65% (1972)

64% (1980)

60% (1976)

62% (1976)

71% (1978)

60% (1977)

53% (1979)

63% (1979)

56% (1977)

54% (1972)

58% (1978)

61% (1974)

70% (1975)

59% (1972)

64% (1973)

65% (1978)

42% (1978)

50% (1977)