calculate the number of times patient 14836 had a chest tube #1 since 506 days ago.
select count(*) from outputevents where outputevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 14836 ) ) and outputevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'chest tube #1' and d_items.linksto = 'outputevents' ) and datetime(outputevents.charttime) >= datetime(current_time,'-506 day')