Year Percent of GDP 2004-01-01 16.5350 2005-01-01 28.2088 2006-01-01 22.4281 2007-01-01 19.5286 2008-01-01 17.1549 2009-01-01 21.6504 2010-01-01 23.2912 2011-01-01 20.4599 2012-01-01 19.3749 2013-01-01 21.0765 2014-01-01 21.9630 2015-01-01 22.6447 2016-01-01 23.9955