Year Percent 2003-01-01 0.1851600000000000 2004-01-01 1.1942400000000000 2005-01-01 1.7870099999999998 2006-01-01 2.4870300000000000 2007-01-01 2.9420200000000000 2008-01-01 2.6584800000000000 2009-01-01 5.3056300000000010 2010-01-01 5.3641500000000000 2011-01-01 5.3636400000000000 2012-01-01 4.3986700000000000 2013-01-01 6.4570700000000000 2014-01-01 6.9620100000000000 2015-01-01 7.6482800000000010 2016-01-01 6.6098500000000000