57% (1985)

70% (1980)

60% (1975)

67% (1978)

78% (1974)

77% (1985)

68% (1979)

67% (1984)

67% (1982)

67% (1988)

63% (1961)

57% (1979)

62% (1985)

82% (1975)

70% (1978)

60% (1979)

80% (1985)

73% (1980)

55% (1975)

63% (1985)