what is patient 78076's monthly maximum creatinine level until 09/2102?
select max(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 78076 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'creatinine' ) and strftime('%y-%m',labevents.charttime) <= '2102-09' group by strftime('%y-%m',labevents.charttime)