Year	% of total primary
1970	64.4034271240234
1971	64.6664810180664
1972	63.2876014709473
1973	62.4210205078125
1974	59.424430847168
1975	57.1294708251953
1976	55.129768371582
1977	52.5649681091309
1978	50.5524406433105
1979	48.320240020752
1980	46.3824882507324
1981	46.5032806396484
1982	46.5654296875
1983	46.5145683288574
1984	45.9461212158203
1985	46.2229804992676
1986	46.4195289611816
1987	46.567928314209
1988	46.7863502502441
1989	46.8115386962891
1990	46.9177017211914
1991	46.696590423584
1992	45.5020904541016
1993	44.5144882202148
1994	43.8679695129395
1995	42.7350082397461
1996	42.8464813232422
1997	41.5454902648926
1998	42.9441719055176
1999	43.9623985290527
2000	43.7410697937012
2001	43.3615493774414
2002	43.4774703979492
2003	43.5503005981445
2004	44.2171897888184
2005	44.4021301269531
2006	44.0439682006836
2007	43.0543594360352
2008	43.0485916137695
2009	38.6496391296387
2010	33.848949432373
2011	29.4365406036377
2012	25.2025203704834
2013	20.70339012146
2014	16.1855792999268
2015	11.3405199050903
2016	11.6848697662354
2017	11.5471696853638
2018	11.0226497650146
2019	10.8717498779297
2020	11.4457998275757
2021	11.6116304397583