61% (1985)

61% (1988)

64% (1999)

66% (1980)

62% (1981)

51% (2005)

50% (1995)

49% (2008)

65% (1978)

58% (1990)

50% (1994)

67% (1964)

61% (1986)

51% (1962)

63% (1992)

57% (2002)

49% (1963)

60% (1977)

52% (1973)

65% (1983)