Year	% of total primary
1993	3.17309999465942
1994	3.61349010467529
1995	3.83132004737854
1998	3.83982992172241
1999	3.85847997665405
2000	3.87104988098145
2001	3.8578999042511
2002	4.04344987869263
2003	4.22845983505249
2004	4.46163988113403
2005	4.86062002182007
2006	5.11348009109497
2007	5.2985200881958
2008	5.52878999710083
2009	5.75238990783691
2010	5.95092010498047
2011	6.15354013442993
2012	6.29117012023926
2013	6.49315977096558
2014	6.72277021408081
2015	7.05288982391357
2016	7.32173013687134
2017	7.70094013214111
2018	8.04032039642334
2019	8.23104953765869
2020	8.34066963195801
2021	8.08419036865234
2022	8.93595027923584