62% (1997)

59% (2009)

52% (2003)

53% (1996)

65% (1997)

60% (1998)

56% (2008)

52% (2004)

54% (2010)

57% (2005)

40% (1991)

55% (1996)

64% (2001)

51% (1997)

49% (1995)

44% (2011)

50% (1993)

40% (2009)

61% (1998)

56% (1996)