58% (1993)

39% (1994)

55% (1989)

44% (1990)

55% (1986)

57% (1989)

59% (1987)

73% (1989)

37% (1988)

63% (1987)

69% (1990)

56% (1988)

40% (1989)

47% (1988)

61% (1988)

44% (1987)

38% (1992)

60% (1990)

56% (1988)

40% (1987)