when did patient 90663 get admitted into the hospital via clinic referral/premature for the first time during this year?
select admissions.admittime from admissions where admissions.subject_id = 90663 and admissions.admission_location = 'clinic referral/premature' and datetime(admissions.admittime,'start of year') = datetime(current_time,'start of year','-0 year') order by admissions.admittime asc limit 1