Year Percent of GDP 2004-01-01 18.1688 2005-01-01 20.3719 2006-01-01 21.4889 2007-01-01 23.3325 2008-01-01 24.3309 2009-01-01 30.1725 2010-01-01 31.8858 2011-01-01 31.1947 2012-01-01 36.4054 2013-01-01 37.6007 2014-01-01 41.7756 2015-01-01 48.1270 2016-01-01 44.4842 2017-01-01 47.5734