71% (1971)

61% (1998)

61% (2010)

68% (1997)

64% (1997)

56% (1993)

59% (1994)

68% (1998)

58% (1997)

62% (1993)

55% (1998)

59% (1993)

59% (1998)

50% (1994)

56% (1993)

56% (1998)

46% (1991)

0% (1989)

80% (1976)

66% (1926)