72% (2016)

75% (2001)

69% (1975)

73% (1977)

70% (1974)

62% (1973)

68% (1985)

64% (1970)

67% (1973)

74% (1983)

60% (1974)

64% (1972)

53% (1984)

70% (1973)

61% (1977)

56% (1974)

60% (1994)

68% (1974)

64% (1987)

47% (1980)