###HUMAN: what was patient 13897's daily average value of body weight until 07/2104?, ###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 = 13897)) AND chartevents.itemid IN (SELECT d_items.itemid FROM d_items WHERE d_items.label = 'admit wt' AND d_items.linksto = 'chartevents') AND STRFTIME('%y-%m', chartevents.charttime) <= '2104-07' GROUP BY STRFTIME('%y-%m-%d', chartevents.charttime)