when did patient 13528 receive his or her prescription for the last time since 12/2104?
select prescriptions.startdate from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 13528 ) and strftime('%y-%m',prescriptions.startdate) >= '2104-12' order by prescriptions.startdate desc limit 1