72% (1991)

75% (1992)

58% (1994)

65% (1997)

61% (1994)

60% (1996)

63% (1992)

64% (1998)

63% (1996)

64% (1997)

65% (1993)

48% (1997)

54% (1997)

46% (1996)

56% (1992)

56% (1999)

59% (1991)

56% (1997)

68% (1996)

57% (1998)