Year	% of cohort
1980	96.7358474731445
1981	98.4444198608398
1982	98.8835830688477
1983	96.9662933349609
1984	99.5401382446289
1987	98.0044021606445
1988	97.3998565673828
1989	96.931770324707
1990	98.0416870117188
1992	96.6951599121094
2001	86.8990707397461
2002	98.1359481811523
2004	98.6565322875977
2005	98.2318496704102
2006	98.3020095825195
2013	94.8357086181641
2014	91.6838302612305
2016	96.503532409668
2017	92.8550720214844
2018	94.5498733520508
2019	95.3007888793945
2020	98.739860534668