60% (1997)

67% (2007)

67% (2003)

54% (2012)

68% (2004)

67% (2000)

57% (2004)

47% (2004)

59% (2001)

51% (2003)

59% (2006)

56% (1999)

57% (1993)

0% (1971)

70% (1991)

60% (2009)

25% (2004)

51% (2004)

50% (2001)

65% (2002)