Year	% of total primary
1971	11.2715101242065
1972	10.9614295959473
1973	12.0419502258301
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1988	0
1990	0
1992	1.15601003170013
1993	1.63408994674683
1994	2.11572003364563
1995	1.9653799533844
1996	2.20777010917664
1997	1.99686002731323
1998	2.1077299118042
1999	1.93580996990204
2000	2.0301399230957
2001	2.05624008178711
2002	2.02401995658875
2003	2.01531004905701
2004	2.07239007949829
2005	2.35962009429932
2006	2.61537003517151
2007	2.78166007995605
2008	3.00372004508972
2009	3.34356999397278
2010	3.46039009094238
2011	3.80448007583618
2012	4.12913990020752
2013	4.40939998626709
2014	4.53258991241455
2015	4.93105983734131
2016	5.29126977920532
2017	5.68403005599976
2018	6.20187997817993
2019	6.85205984115601
2020	7.35781002044678