Year	% of GDP
1975	17.671933294088056
1976	17.613065246462586
1977	18.014160613327867
1978	17.94269347495199
1979	18.274265393414026
1981	18.855780756599845
1983	18.26656832052899
1984	17.599986436729626
1985	17.6304976133799
1986	17.131870058982592
1987	16.77779342750299
1988	16.021267361954997
1989	16.573520797849298
1990	15.934494445246482
1991	15.730684661246215
1992	16.642956076248083
1993	16.13338911381473
1994	16.63234896575348
1995	16.556770296691298
1996	16.386278508368306
1997	16.692004661717135
1998	14.839399280578426
1999	15.32400628824691
2008	20.033603380372266
2009	18.497593844757656
2010	20.284296548733934
2011	20.548056748419164
2012	20.963051786240825
2013	20.787706815831957
2014	20.047816079938762
2015	19.1586716280698
2016	18.750878854473914
2017	18.93703082572492
2018	19.212083667794406