Year	% of cohort
1971	93.8447418212891
1972	92.8782119750977
1997	95.8065795898438
1998	96.2454299926758
2003	96.3429412841797
2010	98.8585433959961
2011	99.4888381958008
2012	99.2395401000977
2013	99.1884918212891
2014	98.996208190918
2015	99.519416809082
2017	99.4899826049805
2018	99.7527618408203
2019	99.458251953125
2020	99.6307678222656
2021	99.4730606079102