Year	% of total primary
1970	8.61328029632568
1971	9.04916000366211
1972	8.87823963165283
1973	8.75
1974	8.31344032287598
1975	7.76491022109985
1976	7.69495010375977
1977	7.72147989273071
1978	7.75591993331909
1979	7.75539016723633
1980	7.79259014129639
1981	7.88346004486084
1982	8.00201988220215
1983	8.1363000869751
1984	8.24380970001221
1985	8.2747802734375
1986	8.31227016448975
1987	8.35352039337158
1988	8.51644992828369
1989	8.64437007904053
1990	8.76103973388672
1991	8.85904026031494
1992	9.00967979431152
1993	9.17088985443115
1994	9.33078002929688
1995	9.41707038879395
1996	9.53439998626709
1997	9.67899036407471
1998	9.80595016479492
1999	9.99814987182617
2000	10.1578302383423
2001	10.4441995620728
2002	10.5505104064941
2003	11.4393701553345
2004	11.9279203414917
2005	12.7813596725464
2006	13.3973999023438
2007	14.1580400466919
2008	14.6708097457886
2009	15.4016199111938
2010	16.0804691314697
2011	16.9753704071045
2012	17.5937004089355
2013	18.0729103088379
2014	18.5738792419434
2015	18.6791400909424
2016	18.5091209411621
2017	18.9735298156738
2018	20.6297397613525
2019	20.6419696807861
2020	21.0385093688965
2021	20.9266204833984
2022	21.3080406188965