Year Percent 2001-01-01 16.600000000000000 2002-01-01 12.500000000000000 2003-01-01 2.900000000000000 2004-01-01 14.000000000000000 2005-01-01 14.000000000000000 2006-01-01 13.700000000000000 2007-01-01 17.800000000000000 2008-01-01 15.900000000000000 2009-01-01 19.000000000000000 2010-01-01 24.682000000000000 2011-01-01 24.961800000000000 2012-01-01 23.850400000000000 2013-01-01 23.073400000000000 2014-01-01 24.171999999999997 2015-01-01 22.521000000000000 2016-01-01 23.051300000000000