Year	% of total primary
1970	3.94429993629456
1971	2.76861000061035
1972	2.19537997245789
1973	2.06819009780884
1974	2.08466005325317
1975	2.26225996017456
1976	2.25620007514954
1977	1.99091005325317
1981	0.889230012893677
1982	0.855780005455017
1983	0.342409998178482
1988	0.9026700258255
1991	0.686129987239838
1999	6.95415019989014
2000	6.78107023239136
2001	6.69752979278564
2002	6.65077018737793
2003	6.83959007263184
2004	6.91558980941772
2005	6.89970016479492
2006	7.08418989181519
2007	7.65953016281128
2008	7.83329010009766
2010	8.5571403503418
2011	8.91763019561768
2012	9.12788963317871
2013	9.56311988830566
2014	10.1792001724243
2015	10.7850799560547
2016	11.3798904418945
2017	11.9192600250244
2018	12.1813802719116
2019	12.3818502426147
2020	11.9771099090576
2021	11.3419599533081