when did patient 80645 enter the hospital for the first time via transfer from hosp/extram the previous year?
select admissions.admittime from admissions where admissions.subject_id = 80645 and admissions.admission_location = 'transfer from hosp/extram' and datetime(admissions.admittime,'start of year') = datetime(current_time,'start of year','-1 year') order by admissions.admittime asc limit 1