Year	% of total primary
1970	16.3888607025146
1971	17.5393009185791
1972	15.0079898834229
1973	14.3878498077393
1974	13.5181999206543
1975	12.869270324707
1976	12.0590000152588
1977	11.6885404586792
1978	11.5874795913696
1979	11.2365102767944
1980	10.7880001068115
1981	10.7135696411133
1982	10.9297199249268
1983	10.6394100189209
1984	10.4018497467041
1985	10.1915397644043
1986	9.66187000274658
1987	9.39422035217285
1988	9.06886959075928
1989	8.79395961761475
1990	8.64305973052979
1991	8.27029037475586
1992	8.37913990020752
1993	8.19719982147217
1994	7.93045997619629
1995	8.36507034301758
1996	8.22994041442871
1997	7.96721982955933
1998	8.15550994873047
1999	8.09144973754883
2000	8.1178503036499
2001	8.24915981292725
2002	8.06077003479004
2003	7.78807020187378
2004	7.78459978103638
2005	7.84438991546631
2006	8.07059001922607
2007	8.36804962158203
2008	8.62623977661133
2009	9.12108993530273
2010	9.59095001220703
2011	11.0632295608521
2012	11.3249397277832
2013	11.7772102355957
2014	11.7880897521973
2015	12.1701498031616
2016	12.4408102035522
2017	13.4930000305176
2018	14.2681198120117
2019	14.10498046875
2020	13.842209815979
2021	14.1092700958252
2022	14.2002096176147