what is the average mchc value of patient 16066 in 01/2104?
select avg(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 16066 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'mchc' ) and strftime('%y-%m',labevents.charttime) = '2104-01'