Year	% of total primary
1971	11.5697898864746
1973	12.6100397109985
1981	17.8288593292236
1982	18.785530090332
1983	12.6036996841431
1984	12.5723495483398
1985	21.246000289917
1986	24.0525207519531
1991	21.2472400665283
1992	22.1242294311523
1993	22.8793907165527
1994	20.6308708190918
1995	19.5287208557129
1996	18.0317306518555
1997	14.648699760437
1998	15.9735898971558
1999	15.7939195632935
2005	17.278299331665
2006	17.0865592956543
2007	19.3261699676514
2008	20.8034896850586
2009	22.1646099090576
2010	23.1348896026611
2011	23.2651691436768
2012	23.473819732666
2013	23.519889831543
2014	23.5600490570068
2015	22.5094299316406
2016	22.7505893707275
2017	22.8381404876709
2018	23.253080368042
2019	21.8505306243896
2020	22.9320297241211
2021	16.5128307342529
2022	19.3760795593262