61% (1977)

64% (2000)

64% (2006)

62% (1994)

40% (1989)

59% (1984)

56% (1983)

55% (1995)

65% (1978)

100% (1976)

68% (1977)

68% (1978)

59% (2011)

55% (1985)

50% (1997)

59% (1976)

53% (2002)

49% (1978)

56% (1996)

62% (1950)