calculate the number of patients who have received a laboratory test for neutrophils since 1 year ago.
select count( distinct admissions.subject_id ) from admissions where admissions.hadm_id in ( select labevents.hadm_id from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'neutrophils' ) and datetime(labevents.charttime) >= datetime(current_time,'-1 year') )