78% (1979)

82% (1998)

59% (2009)

66% (1981)

69% (1997)

67% (2009)

72% (1980)

73% (1987)

74% (1982)

58% (1990)

59% (1985)

69% (1986)

42% (1986)

64% (2003)

63% (1989)

65% (1987)

56% (1982)

56% (1988)

63% (1984)

66% (1989)