74% (2002)

70% (1992)

60% (2004)

61% (1999)

73% (1994)

71% (1988)

77% (1999)

71% (1979)

76% (1986)

62% (1997)

70% (2002)

66% (2007)

61% (1974)

67% (1989)

78% (1969)

61% (1981)

77% (1986)

63% (1980)

61% (1995)

70% (1995)