75% (2008)

69% (2003)

74% (1995)

67% (1993)

72% (1999)

68% (1990)

66% (1998)

62% (1995)

69% (1989)

64% (2005)

71% (1993)

73% (1982)

68% (2007)

72% (1985)

55% (1999)

64% (2002)

64% (1991)

59% (2001)

57% (1988)

66% (1981)