Year Percent of GDP 2004-01-01 23.4354 2005-01-01 23.1707 2006-01-01 24.0582 2007-01-01 23.0653 2008-01-01 24.2215 2009-01-01 25.7260 2010-01-01 27.2130 2011-01-01 29.4811 2012-01-01 29.5361 2013-01-01 29.2225 2014-01-01 29.6785 2015-01-01 30.7923 2016-01-01 31.8012