76% (2007)

70% (2008)

54% (2004)

70% (2007)

70% (2006)

60% (2004)

69% (2007)

57% (2002)

35% (2004)

50% (2006)

59% (1980)

47% (2003)

37% (2003)

62% (2001)

62% (2005)

60% (1978)

30% (2005)

52% (2005)

35% (1969)