Year	% of total primary
1970	4.79894018173218
1971	4.78659009933472
1972	4.72354984283447
1973	4.48413991928101
1974	4.29043006896973
1975	3.96827006340027
1976	3.71072006225586
1977	3.55447006225586
1978	3.53640007972717
1979	3.4998300075531
1980	3.44491004943848
1981	3.40548992156982
1982	3.4125599861145
1983	3.46626996994019
1984	3.49710011482239
1985	3.48727989196777
1986	3.30310988426208
1987	3.37203001976013
1988	3.44850993156433
1989	3.53305006027222
1990	3.58185005187988
1991	3.61270999908447
1992	3.55175995826721
1993	3.58604001998901
1994	3.70121002197266
1995	3.83657002449036
1996	3.96723008155823
1997	4.05469989776611
1998	4.30516004562378
1999	4.5079197883606
2000	4.41029977798462
2001	4.68332004547119
2002	5.02606010437012
2003	5.41456985473633
2004	5.49736976623535
2005	5.85014009475708
2006	6.07290983200073
2007	6.70634984970093
2008	6.69103002548218
2009	7.04757976531982
2010	7.36077976226807
2011	7.71427011489868
2012	7.99762010574341
2013	8.32814979553223
2014	8.70273017883301
2015	9.21726989746094
2016	9.53966045379639
2017	9.79249954223633
2018	10.2476797103882
2019	10.506799697876
2020	10.7452802658081
2021	10.7566299438477
2022	10.663049697876