Year	% of total primary
1971	3.49782991409302
1972	3.93049001693726
1973	4.12906980514526
1974	4.86611986160278
1975	6.53449010848999
1976	7.24410009384155
1977	7.1869797706604
1981	8.3861198425293
1982	9.08850955963135
1983	8.3953104019165
1984	8.24083042144775
1985	8.28495979309082
1986	8.71870040893555
1987	9.07703018188477
1988	9.58905982971191
1989	9.67815971374512
1990	9.11816024780273
1991	8.64943981170654
1992	7.9605598449707
1993	7.13185977935791
1994	7.28911018371582
1995	7.58080005645752
1996	8.41147041320801
1998	10.1775598526001
1999	10.8284902572632
2000	11.3910503387451
2001	12.0284099578857
2002	12.6726903915405
2003	13.0355195999146
2004	12.9633598327637
2005	13.7511701583862
2006	13.6555404663086
2007	13.5807199478149
2008	13.0978498458862
2009	14.2289199829102
2010	14.1657400131226
2011	14.4767503738403
2012	15.5709104537964
2013	16.4825801849365
2014	17.316219329834
2015	18.2838897705078
2016	19.4559497833252
2017	20.0931205749512
2018	20.2964096069336
2019	21.486780166626
2020	23.3867206573486
2021	24.4075508117676
2022	26.3370094299316