count how many times patient 26469 had received a lab urobilinogen test since 6 years ago.
select count(*) from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'urobilinogen' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 26469 ) and datetime(labevents.charttime) >= datetime(current_time,'-6 year')