74% (1992)

76% (1997)

76% (1997)

74% (1993)

71% (1991)

77% (1998)

64% (2009)

71% (1997)

65% (1993)

68% (1994)

75% (1996)

68% (1995)

57% (2004)

62% (1996)

74% (1994)

58% (2009)

62% (1993)

53% (1997)

53% (2003)

64% (1991)