Year Percent of GDP 2004-01-01 20.4786 2005-01-01 22.0075 2006-01-01 20.5738 2007-01-01 23.1734 2008-01-01 27.5909 2009-01-01 27.2133 2010-01-01 27.2745 2011-01-01 25.8601 2012-01-01 26.8813 2013-01-01 30.5864 2014-01-01 30.4954 2015-01-01 34.0018 2016-01-01 31.4240 2017-01-01 34.2226