77% (1997)

79% (1997)

79% (1987)

77% (1992)

79% (1990)

74% (1974)

73% (1989)

66% (1970)

57% (1975)

76% (1991)

71% (1984)

72% (1976)

58% (2000)

55% (1995)

54% (1975)

62% (1973)

58% (1982)

65% (1974)

53% (1976)

67% (1996)