52% (1997)

60% (2007)

48% (2006)

65% (2008)

50% (1991)

67% (1997)

68% (2006)

40% (1991)

0% (1990)

60% (2001)

60% (2005)

71% (2007)

62% (1999)

44% (2002)

0% (1993)