Year	% of cohort
1991	96.6643829345703
1992	96.2959594726562
1993	96.246223449707
1994	96.3006973266602
1995	96.685432434082
1996	96.2286682128906
1997	95.86376953125
1998	96.4805221557617
1999	96.4329071044922
2000	96.831169128418
2001	96.9296722412109
2002	97.1361923217773
2003	97.1914978027344
2004	97.4818115234375
2005	97.6792907714844
2006	97.5955200195312
2007	97.0880432128906
2008	97.0173110961914
2009	97.9848327636719
2010	97.1872787475586
2011	96.5218505859375
2012	96.652961730957
2013	97.2260894775391
2014	95.7418975830078
2015	97.6258010864258
2016	98.4672012329102
2017	98.7207565307617
2018	98.7058181762695
2019	98.5759582519531
2020	98.5147094726562
2021	98.5156173706055