75% (1967)

77% (1979)

57% (1980)

72% (1971)

62% (2004)

58% (1967)

78% (1971)

60% (1980)

55% (1992)

72% (1975)

78% (1974)

69% (2009)

56% (1989)

66% (1976)

68% (1988)

72% (1976)

70% (1989)

71% (1976)

60% (1976)

70% (1990)