what is the average wbc, other fluid value of patient 26922 since 118 months ago?
select avg(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 26922 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'wbc, other fluid' ) and datetime(labevents.charttime) >= datetime(current_time,'-118 month')