61% (1997)

64% (1990)

67% (1988)

68% (1992)

20% (1996)

62% (1990)

56% (1996)

62% (1991)

43% (1990)

47% (1995)

55% (1994)

40% (1989)

52% (1989)

53% (1993)

30% (1992)

72% (1996)

44% (1988)

44% (1995)

24% (1991)

40% (1998)