Year	% of cohort
1996	98.3989715576172
1997	98.3946685791016
1998	99.2618103027344
1999	99.6062393188477
2001	98.4526519775391
2002	99.2274932861328
2008	99.3248596191406
2009	98.8783874511719
2010	98.0779190063477
2011	99.0893020629883
2012	99.5202865600586
2013	99.0564804077148
2014	98.3463897705078
2015	99.5037231445312
2016	99.2481689453125
2017	99.4649429321289
2018	99.8636703491211
2019	99.488639831543
2020	99.9019470214844
2021	99.7673187255859