Year Percent 1999-01-01 2.9906700000000000 2000-01-01 2.6470300000000000 2001-01-01 4.4547800000000000 2002-01-01 4.6526100000000000 2003-01-01 4.5130700000000000 2004-01-01 5.5697000000000000 2005-01-01 4.7901700000000000 2006-01-01 5.3782900000000000 2007-01-01 4.0325900000000000 2008-01-01 3.8230699999999995 2009-01-01 5.6296100000000000 2010-01-01 5.4945600000000000 2011-01-01 5.3562699999999990 2012-01-01 13.4297000000000000 2013-01-01 12.5414000000000000 2014-01-01 18.9261000000000000 2015-01-01 25.1040000000000000 2016-01-01 31.5840000000000000