@JHS I have added the number of students graduated in each quarter to demonstrate that students graduated can’t account for the number of students who disappeared:
2014 Autumn 5724 (38 B.A. + 4 B.S. total 42 graduated)
2015 Winter 5591 ==> reduce by 133 (27 B.A. + 8 B.S. total 35 graduated) ==> **133-42=91 disappeared**
2015 Spring 5395 ==> reduce by 196 (1079 B.A. + 149 B.S. total 1228 graduated) **196-35=161 disappeared**
==> for the year 1228+35+42=1305 which is not far from 1326 reported on https://registrar.uchicago.edu/data-reporting/degrees-awarded/
2015 Autumn 5860 ----> New students come
2016 Winter 5757 ==> reduce by 103
2016 Spring 5539 ==> reduce by another 218
2016 Autumn 5971 ----> New students come
2017 Winter 5838 ==> reduce by 133
2017 Spring 5588 ==> reduce by another 250
2017 Autumn 6286 ----> New students come
2018 Winter 6138 ==> reduce by 148
2018 Spring 5919 ==> reduce by 219
2018 Autumn 6595 > New students come
@surelyhuman : My calculation is different from yours. Please confirm. Thank you.