Year	% of total primary
1971	6.05555009841919
1972	5.74641990661621
1973	5.3023099899292
1974	5.12478017807007
1975	5.11674976348877
1976	5.16655015945435
1977	5.29544019699097
1981	4.83102989196777
1982	4.75668001174927
1983	4.56949996948242
1984	4.49595022201538
1985	4.46752977371216
1986	4.46646022796631
1987	4.31475019454956
1988	3.65090990066528
1989	3.54183006286621
1990	3.58396005630493
1991	3.54509997367859
1992	3.68370008468628
1993	3.68951988220215
1994	3.81574988365173
1995	3.91215991973877
1996	3.94757008552551
1997	4.00771999359131
1999	4.18956995010376
2000	4.18015003204346
2001	4.32687997817993
2002	4.42856979370117
2003	4.22411012649536
2004	4.21020984649658
2005	4.42392015457153
2006	4.32595014572144
2007	4.14537000656128
2008	4.26004981994629
2009	4.15298986434937
2010	4.19156980514526
2011	4.24827003479004
2012	4.02327013015747
2013	3.93720006942749
2020	5.73737001419067
2021	6.08619022369385
2022	6.21412992477417
2023	6.11065006256104