74% (1993)

76% (1987)

71% (1992)

62% (2005)

52% (1995)

57% (2009)

50% (2003)

51% (2001)

58% (1991)

61% (1983)

64% (1998)

61% (1990)

58% (1996)

54% (1988)

58% (1981)

55% (1984)

60% (2000)

49% (1975)

66% (2005)

54% (1979)