Year Percent 1997-01-01 18.5185 1998-01-01 33.3333 1999-01-01 40.0000 2000-01-01 42.1053 2001-01-01 37.5000 2002-01-01 37.1429 2003-01-01 35.4839 2004-01-01 27.4510 2005-01-01 29.2308 2006-01-01 29.3333 2007-01-01 22.3881 2008-01-01 15.0685 2009-01-01 25.7426 2010-01-01 24.5902 2011-01-01 23.4043 2012-01-01 48.1499 2013-01-01 52.8545 2014-01-01 63.0769