Year	% of total primary
1970	76.2493667602539
1971	85.2774505615234
1972	83.3540725708008
1973	83.4528884887695
1974	80.9220809936523
1975	80.4150695800781
1980	79.7578964233398
1981	79.6052093505859
1982	79.5679321289062
1983	79.8207626342773
1984	79.820556640625
1985	80.1141128540039
1986	79.9530334472656
1987	80.2873916625977
1988	80.5435104370117
1989	80.7486724853516
1991	81.3554000854492
1997	82.1108779907227
1998	0
1999	0
2000	0
2001	1.82729005813599
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2009	0.486710011959076
2010	0.238769993185997
2011	1.04913997650146
2012	1.5077999830246
2013	1.67267000675201
2014	1.55051004886627
2015	1.61968994140625
2016	1.67051994800568
2017	1.77341997623444
2019	2.66227006912231