what is the daily average amount of albumin of patient 19175?
select avg(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 19175 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'albumin' ) group by strftime('%y-%m-%d',labevents.charttime)