76% (1989)

64% (1993)

73% (1987)

64% (1991)

52% (1997)

63% (2011)

67% (1990)

71% (1992)

65% (1992)

54% (1998)

63% (2005)

65% (2010)

64% (1992)

74% (1993)

69% (2011)

61% (1993)

71% (1987)

71% (1993)

63% (1995)

66% (2002)