Year	% of GDP
1990	18.259141126981927
1991	19.57735015406081
1992	18.48150517002452
1993	18.705612977504106
1994	19.770179659108358
1995	19.221302829282013
1996	19.954861343880584
1997	20.56486826130482
1998	21.174301376924372
1999	20.69311998786661
2000	19.699091517509608
2001	19.362849475306614
2002	20.716612714227832
2003	19.827064278851758
2004	19.592983373076798
2005	19.72446999004574
2006	20.818328563804112
2007	20.895076428172153
2008	22.644708184872762
2009	22.43107906639738
2010	21.667265933799516
2011	21.38479337036779
2012	21.844685929801205
2013	20.37058110152436
2014	22.499915923187427
2015	22.659509346894573
2016	24.352093585976657
2017	23.79953574296484