81% (1974)

79% (1975)

79% (1975)

79% (1977)

79% (1978)

57% (1969)

70% (1978)

60% (1981)

70% (1974)

80% (1976)

75% (1974)

42% (2005)

71% (1980)

79% (1976)

79% (1977)

67% (1979)

81% (1976)

65% (1972)

70% (1979)

30% (2008)