81% (1979)

82% (1986)

70% (1979)

60% (1977)

50% (1989)

53% (1981)

67% (1987)

67% (1986)

63% (1981)

10% (1988)

72% (1976)

0% (1970)

60% (1976)

66% (1978)

62% (1982)

72% (1990)

77% (1982)

67% (1976)

70% (1986)

80% (1982)