Year	% of cohort
1999	93.845703125
2001	95.8191528320312
2004	99.7116165161133
2005	99.4008636474609
2006	99.498649597168
2007	99.574821472168
2008	99.6605606079102
2009	99.6420211791992
2010	99.5177536010742
2011	99.3345489501953
2012	98.9404373168945
2013	99.4176635742188
2014	99.1757202148438
2015	99.2369613647461
2016	99.7548294067383
2017	99.7647094726562
2018	99.8151092529297
2019	99.8667831420898
2020	99.1628799438477