Year	% of total primary
1970	8.15676975250244
1971	8.07131004333496
1972	7.83217000961304
1973	7.54090023040771
1974	7.19461011886597
1975	6.708899974823
1976	6.42601013183594
1977	5.85722017288208
1978	5.34978008270264
1979	4.74241018295288
1980	4.51163005828857
1981	4.2007098197937
1982	4.06777000427246
1983	3.85324001312256
1984	4.21381998062134
1985	3.83911991119385
1986	3.52355003356934
1987	3.48819994926453
1988	3.29351997375488
1989	3.30370998382568
1990	3.36854004859924
1991	3.24421000480652
1992	3.37089991569519
1993	3.51234006881714
1994	3.79274988174438
1995	3.77301001548767
1996	4.2436900138855
1997	4.36554002761841
1998	4.4850001335144
1999	4.67564010620117
2000	4.92518997192383
2001	5.23813009262085
2002	5.36279010772705
2003	5.48308992385864
2004	5.49484014511108
2005	5.74259996414185
2006	6.12584018707275
2007	6.45635986328125
2008	6.76722002029419
2009	7.07630014419556
2010	7.29812002182007
2011	7.549880027771
2012	7.73323011398315
2013	7.8263201713562
2014	8.08870983123779
2015	8.76624011993408
2016	8.87205028533936
2017	9.2532901763916
2018	9.53067970275879
2019	9.81099033355713
2020	10.0721597671509
2021	9.60830020904541
2022	9.69509029388428