Year	% of cohort
2006	97.7819595336914
2007	95.8364334106445
2008	94.7837066650391
2009	94.3299331665039
2010	91.6359405517578
2011	93.9323883056641
2012	95.0249710083008
2013	98.1642227172852
2014	97.2496719360352
2016	98.7967224121094
2018	97.2568817138672
2019	98.263801574707
2020	98.4870834350586