Year	% of GDP
1991	9.44995668372018
1992	9.89643190520539
1996	11.9524434773127
1997	10.6743396515329
1998	10.4490563885636
1999	10.1376254481192
2000	13.1454805193329
2001	13.5920467692029
2002	13.9275515920854
2003	14.4461378999674
2004	14.5704959564241
2005	15.2462528233201
2006	15.5698037731719
2007	15.7983539736345
2008	16.444614798061
2009	15.8892999757343
2010	16.7665691943103
2011	16.6317546239275
2012	16.6361988721364
2013	17.6452320522123
2014	17.2930493155001
2015	17.3672409750699
2016	18.4293632432489
2017	18.2469753805857