74% (1993)

71% (1992)

77% (1987)

57% (2009)

50% (2003)

63% (2005)

58% (1996)

55% (1984)

57% (1988)

52% (1995)

61% (1990)

62% (1983)

66% (2005)

77% (1969)

60% (2000)

49% (2007)

55% (1979)

57% (1991)

57% (1989)

70% (1998)