Year	% of GDP
1990	19.218640344706593
1991	17.974095501889213
1992	17.47586528709711
1993	16.37452363559707
1994	16.540061213815
1995	15.915656300744715
1996	16.838435682350717
1997	16.532888825867
1998	16.304719306010835
1999	16.92164764673098
2000	14.927868762583266
2001	15.509773247564107
2002	16.014231057407994
2003	16.27688756362062
2004	16.332155769613212
2005	17.845773364270094
2006	18.428332592101437
2007	19.597675243949713
2008	19.787039269568332
2009	20.02666294493935
2010	21.916511281880542
2011	21.56875122794882
2012	20.655790307159382
2013	21.50673851685482
2014	22.4906146319158
2015	22.181766247019628
2016	22.393097258849533
2017	23.800406904141013