Year	% of total primary
1972	4.46396017074585
1973	4.23081016540527
1974	4.05212020874023
1975	3.72663998603821
1976	3.47595000267029
1977	3.32628011703491
1978	3.32788991928101
1979	3.30938005447388
1980	3.26740002632141
1981	3.22841000556946
1982	3.23686003684998
1983	3.29187989234924
1984	3.31414008140564
1985	3.29678010940552
1986	3.30622005462646
1987	3.37485003471375
1988	3.44762992858887
1989	3.5279700756073
1990	3.57365989685059
1991	3.59807991981506
1992	3.52006006240845
1993	3.54574990272522
1994	3.65698003768921
1995	3.76993989944458
1996	3.90288996696472
1997	3.98598003387451
1998	4.25272989273071
1999	4.46639013290405
2000	4.35686016082764
2001	4.64850997924805
2002	5.0139799118042
2003	5.43586015701294
2004	5.51873016357422
2005	5.89804983139038
2006	6.13574981689453
2007	6.81576013565063
2008	6.78240013122559
2009	7.15442991256714
2010	7.49866008758545
2011	7.86488008499146
2012	8.15106010437012
2013	8.48886013031006
2014	8.90342998504639
2015	9.46424961090088
2016	9.80251026153564
2017	10.0664596557617
2018	10.5514297485352
2019	10.8246097564697
2020	11.0669097900391
2021	11.0642995834351
2022	10.9586200714111