55% (1992)

66% (2009)

61% (1982)

63% (2006)

71% (1981)

73% (1975)

59% (2007)

67% (1977)

55% (1985)

61% (2003)

64% (1997)

61% (2000)

71% (1977)

66% (1992)

67% (1991)

52% (1994)

57% (2005)

60% (2007)

68% (2008)

43% (1994)