64% (1999)

64% (1988)

62% (1981)

52% (2005)

50% (1995)

61% (1985)

67% (1964)

58% (1990)

66% (1978)

63% (1992)

66% (1980)

51% (1994)

57% (2002)

60% (1977)

49% (1963)

52% (1962)

62% (1986)

52% (1973)

65% (1983)

49% (2008)