83% (1994)

78% (1991)

76% (2000)

79% (1998)

74% (1989)

75% (2002)

73% (2003)

76% (1997)

72% (1996)

77% (1992)

74% (1999)

66% (2000)

76% (2002)

70% (1995)

59% (2005)

61% (2004)

71% (2001)

68% (1988)

70% (1995)

75% (2006)