67% (1993)

75% (2008)

69% (2003)

74% (1995)

72% (1999)

64% (2005)

62% (1995)

64% (1991)

68% (1990)

73% (1982)

66% (1998)

61% (1986)

68% (2007)

72% (1985)

56% (1999)

69% (1989)

64% (2002)

71% (1993)

65% (2001)

60% (2001)