80% (1996)

68% (1994)

72% (1998)

76% (1996)

71% (1997)

70% (1995)

67% (1985)

73% (1996)

70% (1990)

69% (1998)

73% (1993)

72% (1992)

66% (1999)

62% (1998)

62% (1994)

70% (1990)

74% (1990)

50% (1985)

57% (1993)

0% (1970)