75% (1980)

65% (1990)

72% (1989)

65% (1982)

61% (1986)

69% (1973)

65% (1987)

62% (1983)

56% (1999)

72% (1976)

63% (1976)

59% (1978)

55% (1980)

64% (1990)

60% (1996)

72% (1966)

72% (1968)

59% (1980)

69% (1977)

63% (1988)