69% (1975)

53% (1984)

74% (2006)

75% (1994)

65% (1986)

69% (1964)

64% (1970)

61% (1977)

60% (1974)

66% (1962)

70% (2009)

58% (1969)

60% (2005)

66% (1963)

39% (1974)

66% (1960)

70% (1967)

77% (2010)

54% (1959)

46% (1991)