61% (1998)

60% (2007)

69% (2010)

72% (2006)

65% (2000)

72% (2000)

69% (1993)

65% (2005)

62% (1988)

69% (2003)

70% (1987)

65% (1996)

62% (2003)

61% (1998)

63% (2002)

57% (1992)

63% (1984)

69% (1998)

62% (1987)

67% (1996)