Year	% of cohort
1991	97.0571212768555
1992	96.4070205688477
1993	96.1771621704102
1994	96.2065505981445
1995	96.7123184204102
1996	95.9010620117188
1997	95.3230361938477
1998	96.2586898803711
1999	96.0842666625977
2000	96.6045303344727
2001	96.7024536132812
2002	96.9793472290039
2003	96.8604278564453
2004	97.2449111938477
2005	97.614387512207
2006	97.4717712402344
2007	96.7202301025391
2008	96.4519882202148
2009	98.6367797851562
2010	97.0912475585938
2011	95.8197937011719
2012	96.1874389648438
2013	97.0927124023438
2014	94.2602386474609
2015	97.4496002197266
2016	98.5273666381836
2017	98.9130401611328
2018	98.8766326904297
2019	98.6401977539062
2020	98.6319427490234
2021	98.6331787109375