Year	% of cohort
2006	97.6623992919922
2007	98.3616714477539
2008	98.1091918945312
2009	98.5626678466797
2010	98.0668792724609
2011	98.3980407714844
2012	99.2175216674805
2013	98.3003311157227
2014	98.3570709228516
2015	98.1122207641602
2016	98.5300521850586
2017	99.3825607299805
2018	98.7380294799805
2019	97.5342407226562
2020	98.3218536376953
2021	99.3944625854492