64% (1991)

39% (1994)

67% (1990)

63% (1992)

48% (1987)

54% (1988)

52% (1986)

59% (1988)

64% (1994)

64% (1993)

58% (1989)

33% (1988)

58% (1990)

58% (1996)

62% (1988)

60% (1989)

55% (1987)

53% (1987)

59% (1989)

52% (1987)