when was the first hospital admission that patient 15209 was admitted to via the transfer from hosp/extram in this year?
select admissions.admittime from admissions where admissions.subject_id = 15209 and admissions.admission_location = 'transfer from hosp/extram' and datetime(admissions.admittime,'start of year') = datetime(current_time,'start of year','-0 year') order by admissions.admittime asc limit 1