Year	% of total secondary
2000	20.1099300384521
2007	18.9844303131104
2010	18.2788105010986
2011	19.5052700042725
2012	16.7123908996582
2014	17.8779201507568
2015	18.4020900726318
2017	18.1655807495117
2018	17.9735202789307