68% (1986)

73% (1988)

71% (1989)

56% (1994)

65% (1982)

73% (1983)

66% (1988)

68% (1983)

73% (1987)

71% (1981)

67% (1986)

54% (1989)

68% (1980)

58% (1993)

69% (1985)

61% (1986)

72% (1982)

60% (1976)

66% (1990)

60% (1988)