83% (1984)

90% (1986)

80% (1980)

77% (1987)

90% (1983)

65% (1983)

70% (1982)

60% (1969)

44% (1980)

50% (1975)

52% (1986)

77% (1983)

90% (1968)

65% (1980)

90% (1987)

80% (1981)

73% (1969)

58% (1991)

50% (1991)

60% (1984)