when did patient 10624 receive a neutrophils lab test, the first time, in 12/2105?
select labevents.charttime from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'neutrophils' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 10624 ) and strftime('%y-%m',labevents.charttime) = '2105-12' order by labevents.charttime asc limit 1