Year	% of total primary
1970	8.04265975952148
1971	7.96358013153076
1972	7.73709011077881
1973	7.46238994598389
1974	7.13393020629883
1975	6.67979001998901
1976	6.42306995391846
1977	5.90195989608765
1978	5.43538999557495
1979	4.87696981430054
1980	4.6655101776123
1981	4.38653993606567
1982	4.29089021682739
1983	4.12485980987549
1984	4.49868011474609
1985	4.17870998382568
1986	3.91797995567322
1987	3.90509009361267
1988	3.76202011108398
1989	3.81223011016846
1990	3.91468000411987
1991	3.69839000701904
1992	3.84985995292664
1993	4.00961017608643
1994	4.30777978897095
1995	4.32095003128052
1996	4.75699996948242
1997	4.87476015090942
1998	5.00495004653931
1999	5.19692993164062
2000	5.42976999282837
2001	5.73311996459961
2002	5.88898992538452
2003	5.99828004837036
2004	6.07002019882202
2005	6.36482000350952
2006	6.80966997146606
2007	7.21404981613159
2008	7.57934999465942
2009	7.93919992446899
2010	8.60324954986572
2011	8.90505027770996
2012	9.14398956298828
2013	9.22751045227051
2014	9.53505039215088
2015	10.2359504699707
2016	10.3993501663208
2017	10.6944799423218
2018	10.8613500595093
2019	11.1166896820068
2020	11.6437902450562
2021	11.0831699371338
2022	11.1118803024292