calculate the number of times patient 1862 has been tested in the total protein, body fluid laboratory until 4 years ago.
select count(*) from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'total protein, body fluid' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 1862 ) and datetime(labevents.charttime) <= datetime(current_time,'-4 year')