74% (2002)

59% (2004)

70% (1992)

61% (1999)

76% (1999)

71% (1988)

70% (2002)

72% (1994)

76% (1986)

61% (1974)

71% (1979)

66% (2007)

60% (1972)

61% (1995)

77% (1986)

68% (1993)

63% (1980)

68% (1974)

78% (1969)

61% (1981)