60% (2004)

74% (2002)

70% (1992)

71% (1988)

61% (1999)

72% (1994)

76% (1999)

76% (1986)

61% (1974)

70% (2002)

77% (1986)

71% (1979)

78% (1969)

63% (1980)

60% (1972)

67% (1989)

53% (1999)

61% (1995)

66% (2007)

55% (1983)