Year	% of GDP
1972	12.783313373805317
1973	13.243836342128018
1974	13.436442725954567
1975	13.714412811387898
1976	14.406528724277774
1977	14.282719804813413
1978	8.38003592195271
1979	8.910126285428188
1980	9.427543134937356
1981	9.164432091476673
2003	19.955495743527766
2004	20.753995944460783
2005	20.74897386303153
2006	21.1096040487086
2007	22.065177387920905
2008	22.74346659837838
2009	20.420364529253114
2010	20.554920711292876
2011	20.89513057155257
2012	21.18690682263798
2013	22.337943079263418
2014	23.113433542174498
2015	23.36315517135297
2020	22.209912610084494