what is patient 1704's daily maximum mchc level?
select max(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 1704 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'mchc' ) group by strftime('%y-%m-%d',labevents.charttime)