what was the total of prednisone patient 1372 had been prescribed until 69 months ago?
select sum(prescriptions.dose_val_rx) from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 1372 ) and prescriptions.drug = 'prednisone' and datetime(prescriptions.startdate) <= datetime(current_time,'-69 month')