74% (1993)

59% (2007)

65% (2009)

71% (1981)

63% (2006)

67% (2008)

61% (2003)

72% (1975)

66% (1992)

67% (1991)

67% (1977)

62% (1979)

52% (1994)

64% (1997)

61% (2000)

61% (1982)

55% (1985)

61% (2007)

63% (1979)

67% (1976)