calculate how many times patient 65962 has had a troponin t test in the lab until 10/2104.
select count(*) from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'troponin t' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 65962 ) and strftime('%y-%m',labevents.charttime) <= '2104-10'