###HUMAN: tell me the average arterial bp [systolic] of patient 16472 until 08/15/2105?, ###ASSISTANT: SELECT AVG(chartevents.valuenum) FROM chartevents WHERE chartevents.icustay_id IN (SELECT icustays.icustay_id FROM icustays WHERE icustays.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 16472)) AND chartevents.itemid IN (SELECT d_items.itemid FROM d_items WHERE d_items.label = 'arterial bp [systolic]' AND d_items.linksto = 'chartevents') AND STRFTIME('%y-%m-%d', chartevents.charttime) <= '2105-08-15'