79% (1990)

72% (1989)

56% (1991)

71% (1994)

57% (1996)

60% (1997)

64% (1994)

55% (1996)

60% (1996)

76% (1995)

35% (1990)

63% (1994)

48% (1992)

40% (1996)

40% (1997)