76% (1989)

73% (2002)

69% (1989)

68% (2007)

64% (2008)

70% (1990)

71% (1988)

52% (2003)

63% (1996)

70% (1996)

73% (1987)

67% (1993)

70% (1993)

60% (1990)

62% (1998)

65% (1993)

48% (2004)

57% (1976)

66% (2006)

57% (2004)