Year	% of total primary
1971	17.9384098052979
1972	19.7003307342529
1973	19.0304203033447
1974	17.3781890869141
1975	17.313009262085
1976	17.105110168457
1981	15.9011096954346
1984	16.0648498535156
1993	15.9391202926636
1994	19.0615997314453
1995	19.5326690673828
1996	19.6613597869873
1997	19.8149299621582
1998	20.2211399078369
1999	21.2337608337402
2000	21.7953491210938
2001	22.6681995391846
2002	27.4032096862793
2003	27.9176692962646
2004	28.1567497253418
2005	28.785400390625
2006	28.5509605407715
2007	28.1680603027344
2008	25.3763999938965
2009	26.1543102264404
2010	25.8706302642822
2011	25.2765998840332
2012	25.1622695922852
2013	24.2678108215332
2014	24.0028495788574
2015	22.607780456543
2016	22.8291206359863
2017	23.5580101013184
2018	24.2007694244385
2019	24.8779792785645
2020	22.4888896942139
2021	22.2062397003174
2022	23.7440299987793