Year	% of total secondary
1999	1.83913004398346
2000	2.29321002960205
2001	2.94100999832153
2002	3.89638996124268
2004	8.33495044708252
2005	9.57981967926025
2006	10.7207002639771
2007	12.0699701309204
2008	13.8465204238892
2009	15.5929698944092
2010	17.4703598022461
2011	19.3877296447754
2012	20.9669704437256
2013	16.9028091430664
2014	16.2910308837891
2015	16.4246006011963
2016	16.7950000762939
2017	17.8353805541992
2018	17.9242000579834
2019	18.9325904846191
2020	19.2292709350586
2021	19.3415107727051
2022	19.5173797607422