71% (2004)

59% (2001)

64% (1997)

54% (1999)

70% (1978)

69% (1989)

73% (1999)

59% (1998)

60% (1997)

40% (2002)

68% (1985)

63% (1998)

69% (2000)

65% (1986)

57% (1987)

74% (1980)

0% (1973)

0% (1988)