72% (1991)

75% (1992)

61% (1994)

65% (1997)

58% (1994)

63% (1998)

63% (1996)

63% (1992)

60% (1996)

65% (1993)

63% (1998)

56% (1992)

55% (1997)

48% (1997)

57% (1998)

55% (1992)

56% (1999)

59% (1991)

68% (1996)

55% (1997)