Year	% of total primary
1970	8.33277988433838
1971	12.6506500244141
1972	13.3315896987915
1973	13.0533199310303
1974	9.97027969360352
1975	7.14107990264893
1976	8.10328006744385
1977	8.0017204284668
1978	8.37289047241211
1979	7.93307018280029
1980	7.52361011505127
1981	6.73915004730225
1982	6.75580978393555
1983	6.71420001983643
1984	6.73076009750366
1985	6.71353006362915
1986	6.75165987014771
1987	6.63333988189697
1988	7.29525995254517
1989	7.4682297706604
1990	8.06289005279541
1991	8.4567403793335
1992	9.10441017150879
1993	9.45524978637695
1994	9.84609031677246
1995	10.8743495941162
1996	11.363920211792
1997	11.6871404647827
1998	12.216609954834
1999	12.6248197555542
2000	12.9142904281616
2001	13.0967597961426
2002	13.1301403045654
2003	13.1806402206421
2004	13.3090600967407
2005	13.5717496871948
2006	13.5624799728394
2007	13.1764698028564
2008	12.7342500686646
2009	13.1960296630859
2010	13.0288801193237
2011	12.524450302124
2012	12.4445495605469
2013	12.4712495803833
2014	12.3456296920776
2015	12.5549001693726
2016	12.6347503662109
2017	12.7329797744751
2018	13.0886602401733
2019	12.99534034729
2020	12.9863996505737
2021	13.1151695251465
2022	13.144100189209