61% (1985)

63% (1988)

67% (1964)

66% (1978)

63% (1992)

62% (1981)

64% (1999)

49% (1963)

51% (1962)

52% (2005)

62% (1986)

60% (1977)

66% (1980)

50% (1994)

58% (1990)

49% (1961)

65% (1983)

50% (1995)

57% (2002)

49% (2008)