61% (2009)

61% (2013)

65% (1995)

63% (1980)

71% (1981)

67% (1996)

72% (1989)

71% (1992)

71% (1986)

70% (1984)

64% (2002)

70% (1999)

56% (1991)

55% (1987)

60% (1980)

71% (1990)

62% (1999)

68% (2003)

50% (1994)

69% (1987)