calculate the number of times that patient 8204 had a impact w/fiber intake since 03/13/2105.
select count(*) from inputevents_cv where inputevents_cv.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 8204 ) ) and inputevents_cv.itemid in ( select d_items.itemid from d_items where d_items.label = 'impact w/fiber' and d_items.linksto = 'inputevents_cv' ) and strftime('%y-%m-%d',inputevents_cv.charttime) >= '2105-03-13'