Year	Percent
1998-01-01	33.29356003
1999-01-01	32.35613632
2000-01-01	29.40125275
2001-01-01	31.41112518
2002-01-01	33.98876572
2003-01-01	31.99208641
2004-01-01	31.25000000
2005-01-01	31.13682175
2006-01-01	27.18236732
2007-01-01	27.51454735
2008-01-01	39.58560562
2009-01-01	41.94528961
2010-01-01	46.52619553
2011-01-01	50.31518555
2012-01-01	53.96014404
2013-01-01	49.30313492