Year	% of total primary
1971	33.9056015014648
1972	33.3801307678223
1973	33.5527191162109
1974	31.9842891693115
1975	30.0067100524902
1976	28.5752105712891
1981	24.1469802856445
1982	23.6545906066895
1983	23.0157108306885
1984	22.6695308685303
1985	22.4042205810547
1986	23.3674297332764
1987	23.2547798156738
1988	23.4898700714111
1989	23.7862396240234
1990	23.8136005401611
1991	24.943510055542
1992	24.5986499786377
1994	23.8289604187012
1995	24.8742694854736
1996	29.012300491333
1999	35.5636787414551
2000	36.9206504821777
2001	39.7136611938477
2002	40.8667106628418
2003	40.7200393676758
2004	40.1776504516602
2005	41.7388496398926
2006	42.7665214538574
2007	42.2372589111328
2008	42.9134902954102
2010	33.7340393066406
2011	30.3238506317139
2012	28.2960605621338
2013	28.3713893890381
2014	27.4280204772949
2016	29.1660404205322
2017	30.1708297729492
2018	30.8587608337402
2019	32.2629890441895
2020	33.1475982666016
2021	33.001220703125
2022	33.1341896057129