Year	% of total primary
1971	6.98983001708984
1972	6.97088003158569
1973	6.91676998138428
1974	7.00612020492554
1976	6.78850984573364
1981	7.2424201965332
1982	7.29483985900879
1983	7.8761100769043
1984	7.27952003479004
1985	7.36448001861572
1986	7.3578200340271
1987	7.30672979354858
1988	7.375
1989	7.43137979507446
1990	7.49997997283936
1991	7.12658023834229
1992	7.10000991821289
1993	7.09999990463257
1994	7.58311986923218
1995	7.57905006408691
1996	7.25030994415283
1997	7.07714986801147
1999	6.95991992950439
2000	6.5616397857666
2001	7.01560020446777
2002	6.71752977371216
2003	6.83390998840332
2004	6.96195983886719
2005	6.96524000167847
2006	6.82113981246948
2007	6.97749996185303
2008	6.93364000320435
2009	6.90077018737793
2010	6.89102983474731
2011	6.9266300201416
2012	6.92061996459961
2013	6.70048999786377
2014	6.54480981826782
2015	6.40339994430542
2016	6.30742979049683
2017	6.02327013015747
2018	5.97840976715088
2019	5.97503995895386
2020	6.03356981277466
2021	6.11532020568848