Year	% of cohort
2001	99.7519226074219
2002	99.6517181396484
2003	98.7120590209961
2004	99.4360275268555
2005	99.4695892333984
2007	99.203857421875
2008	100
2010	99.3008804321289
2011	99.8176574707031
2012	99.5258178710938
2013	99.7292785644531
2014	99.8091125488281
2015	99.3660430908203
2016	99.4350128173828
2017	99.7543029785156
2018	98.989990234375
2019	99.6870498657227
2020	100