Year	% of total primary
1970	12.9702997207642
1971	12.8649196624756
1972	12.6960697174072
1973	12.305549621582
1974	12.0151996612549
1975	11.7565402984619
1976	11.2198295593262
1977	10.4977703094482
1978	9.7679500579834
1979	9.2759895324707
1980	8.94670009613037
1981	8.81048011779785
1982	8.85778999328613
1983	8.74726963043213
1984	8.72371006011963
1985	8.80562019348145
1986	8.847900390625
1987	8.70578956604004
1988	8.71595001220703
1989	8.74600982666016
1990	8.85671043395996
1991	8.75084018707275
1992	9.20046997070312
1993	9.10216045379639
1994	9.10581970214844
1995	10.0886898040771
1996	10.238730430603
1997	10.3674898147583
1998	10.8065395355225
1999	11.0129499435425
2000	11.3509798049927
2001	11.3452196121216
2002	10.9577102661133
2003	10.4713897705078
2004	10.4874095916748
2005	10.5749502182007
2006	10.5075101852417
2007	10.5180797576904
2008	10.630220413208
2009	11.013970375061
2010	11.1880903244019
2011	11.0287303924561
2012	11.2161903381348
2013	11.5619401931763
2014	11.7052602767944
2015	12.2972002029419
2016	12.6563196182251
2017	13.0580902099609
2018	13.2195901870728
2019	13.2180004119873
2020	13.0836601257324
2021	13.3365497589111
2022	13.4570503234863