74% (1993)

71% (1992)

77% (1987)

57% (2009)

51% (2001)

50% (2003)

52% (1995)

62% (2005)

61% (1990)

58% (1996)

61% (1983)

58% (1981)

58% (1991)

66% (2005)

55% (1984)

54% (1988)

60% (2000)

49% (2007)

77% (1969)

59% (1995)