Year	% of total primary
1971	22.563060760498
1972	21.2686595916748
1973	19.9331703186035
1974	18.0431709289551
1975	16.5484600067139
1976	13.1913204193115
1981	9.01965045928955
1982	8.15517044067383
1983	7.35575008392334
1984	8.15672969818115
1985	5.47640991210938
1986	9.88418006896973
1987	9.32341003417969
1988	9.26016044616699
1989	10.1364297866821
1990	11.1351900100708
1991	8.89105987548828
1992	9.30498027801514
1993	9.06861972808838
1994	9.96819019317627
1995	8.30288028717041
1996	7.19432020187378
1997	7.95749998092651
1998	7.96679019927979
1999	8.52752017974854
2000	6.73718976974487
2001	10.5066995620728
2002	10.9947900772095
2003	13.855580329895
2004	15.4619903564453
2005	14.6591396331787
2006	12.7677001953125
2007	14.3240299224854
2008	13.644829750061
2009	9.98272037506104
2011	11.2424602508545
2012	10.9381904602051
2013	12.0723400115967
2014	12.6914300918579
2015	10.4353399276733
2016	9.84698009490967
2017	10.8931903839111
2018	13.5013303756714
2019	17.8658199310303
2020	18.0851707458496
2021	17.8374404907227
2022	17.8979396820068