Year	% of total primary
1971	7.80375003814697
1972	7.41872978210449
1974	7.15771007537842
1975	5.27850008010864
1976	5.95164012908936
1977	5.00108003616333
1978	4.97396993637085
1981	4.8737998008728
1982	5.07508993148804
1983	5.05073022842407
1984	4.87700986862183
1985	4.77889013290405
1986	5.04320001602173
1987	5.24331998825073
1988	5.46442985534668
1989	5.69511985778809
1990	5.96900987625122
1991	6.15059995651245
1992	6.34898996353149
1993	6.39617013931274
1994	6.37473011016846
1995	6.33683013916016
1996	6.18296003341675
1997	6.32538986206055
1999	7.03844976425171
2000	7.386549949646
2001	7.74100017547607
2002	7.94508981704712
2003	8.01517963409424
2004	8.07124042510986
2005	8.0467700958252
2006	8.07201957702637
2007	8.10725975036621
2008	8.23180961608887
2009	8.28026008605957
2010	8.23478031158447
2011	8.25887966156006
2012	8.34605979919434
2013	8.52283000946045
2014	8.73134994506836
2015	8.7910099029541
2016	8.96595001220703
2017	9.26852989196777
2018	9.55245971679688
2019	9.78267955780029
2020	9.91361999511719
2021	8.92127990722656
2022	9.08720970153809