Year Percent of GDP 2010-01-01 18.9471 2011-01-01 18.3294 2012-01-01 18.6523 2013-01-01 18.5502 2014-01-01 18.5396 2015-01-01 18.3981 2016-01-01 21.6746 2017-01-01 22.8588