72% (1991)

76% (1992)

65% (1997)

60% (1994)

64% (1998)

58% (1994)

63% (1996)

60% (1996)

62% (1992)

65% (1993)

63% (1998)

48% (1997)

55% (1997)

56% (1992)

56% (1999)

57% (1998)

55% (1992)

55% (1997)

59% (1991)

68% (1996)