when was the first hospital admission time that patient 42956 was admitted through an emergency room admit last year?
select admissions.admittime from admissions where admissions.subject_id = 42956 and admissions.admission_location = 'emergency room admit' and datetime(admissions.admittime,'start of year') = datetime(current_time,'start of year','-1 year') order by admissions.admittime asc limit 1