72% (1993)

67% (1980)

68% (1986)

72% (1981)

70% (1976)

71% (1982)

73% (1973)

66% (1985)

68% (1967)

65% (1982)

58% (1996)

73% (1974)

74% (1967)

68% (1977)

51% (2007)

54% (2008)

65% (1967)

69% (1979)

61% (1970)

70% (1993)