61% (1997)

68% (1992)

64% (1990)

56% (1996)

68% (1988)

62% (1990)

62% (1991)

20% (1996)

45% (1988)

53% (1993)

43% (1990)

72% (1996)

52% (1989)

47% (1995)

44% (1995)

55% (1994)

30% (1992)

40% (1998)

50% (1996)

40% (1989)