Question: In Harvard University, which year recorded the highest number of first-time, full-time, degree-seeking students in the cohort being tracked, minus any exclusions?
SQL: SELECT T2.year FROM institution_details AS T1 INNER JOIN institution_grads AS T2 ON T2.unitid = T1.unitid WHERE T1.chronname = 'Harvard University' GROUP BY T2.year ORDER BY SUM(T2.grad_cohort) DESC LIMIT 1