68% (2007)

60% (1997)

67% (2003)

55% (2012)

68% (2004)

59% (2001)

47% (2004)

67% (2000)

58% (2004)

56% (1999)

60% (2006)

61% (2009)

67% (2002)

51% (2003)

60% (1993)

0% (1971)

68% (1991)

52% (2001)

25% (2004)

42% (2000)