71% (1991)

74% (1987)

60% (1990)

69% (1987)

77% (1988)

72% (1985)

63% (1990)

84% (1991)

64% (1986)

67% (1980)

70% (1981)

66% (2007)

59% (1997)

63% (1984)

64% (1986)

71% (1988)

69% (1989)

49% (1993)

62% (1994)

58% (1979)