57% (2009)

70% (1992)

74% (1993)

77% (1987)

51% (2001)

58% (1991)

50% (2003)

63% (2005)

66% (2005)

52% (1995)

60% (2000)

60% (1990)

49% (1975)

61% (1983)

58% (1996)

55% (1984)

58% (1981)

64% (1998)

65% (1965)

54% (1979)