Year	% of total primary
1970	12.6846504211426
1971	12.7281703948975
1972	12.471489906311
1973	12.208080291748
1974	12.4502601623535
1975	12.5332202911377
1976	12.5771799087524
1977	12.2644901275635
1978	11.9603204727173
1979	11.6836996078491
1980	11.4813098907471
1981	11.2151699066162
1982	10.9455299377441
1983	10.6634197235107
1984	10.3745098114014
1985	10.1836996078491
1986	9.99036026000977
1987	9.9310998916626
1988	10.000659942627
1989	10.1507396697998
1990	10.2760200500488
1991	9.84739017486572
1992	9.8658504486084
1993	9.95802974700928
1994	9.94474029541016
1995	10.6218500137329
1996	10.7722902297974
1997	10.7805099487305
1998	10.8015098571777
1999	10.7957201004028
2000	10.6965303421021
2001	10.6354598999023
2002	10.6001100540161
2003	10.527979850769
2004	10.5401201248169
2005	10.5538997650146
2006	10.5704698562622
2007	10.6085500717163
2008	10.6212997436523
2009	10.6809797286987
2010	10.8074703216553
2011	10.8012895584106
2012	11.0151300430298
2013	11.2309303283691
2014	11.487250328064
2015	11.8839998245239
2016	12.3573198318481
2017	12.6517200469971
2018	12.8676300048828
2019	13.1668395996094
2020	13.5280799865723
2021	13.9403696060181
2022	13.9194498062134