Year	% of total primary
1981	3.39407992362976
1989	3.66689991950989
1991	3.43011999130249
1992	3.78677010536194
1993	5.0721001625061
1994	4.27784013748169
1995	4.75011014938354
1996	5.4500298500061
1997	5.83306980133057
1998	7.67247009277344
1999	7.24108982086182
2000	10.0796403884888
2001	7.95650005340576
2002	7.28107023239136
2003	5.53132009506226
2004	10.8083400726318
2005	11.7619495391846
2006	13.1422901153564
2008	9.13920021057129
2009	11.6267995834351
2010	13.1964702606201
2011	15.7433004379272
2012	16.3951797485352
2013	16.9622001647949
2014	18.4814395904541
2015	22.1051406860352
2016	22.7382507324219
2017	23.2303504943848
2018	25.3474597930908
2019	27.5957202911377
2020	25.4927806854248
2021	25.017370223999
2022	25.7826194763184