instruction: when was the last time patient 86209 had a chloride test in the lab since 88 months ago?
response: SELECT labevents.charttime FROM labevents WHERE labevents.itemid IN (SELECT d_labitems.itemid FROM d_labitems WHERE d_labitems.label = 'chloride') AND labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 86209) AND DATETIME(labevents.charttime) >= DATETIME(CURRENT_TIME(), '-88 month') ORDER BY labevents.charttime DESC LIMIT 1