72% (1993)

66% (1985)

73% (1974)

67% (1980)

65% (1982)

73% (1973)

67% (1967)

74% (1991)

71% (1982)

70% (1976)

68% (1986)

63% (1980)

58% (1996)

55% (2008)

62% (1980)

72% (1981)

65% (1978)

60% (1970)

62% (1995)

66% (1971)