ขอ paco2 ขั้นต่ำรายวันของผู้ป่วย 018-81471 จนถึง 2104 ไม่จำเป็นต้องใช้ตารางทั้งหมด
give me patient 018-81471's daily minimum paco2 until 2104.It is not neccessary to use all the tables.
 allergy:  allergyid [ number]  patientunitstayid [ number]  drugname [ text]  allergyname [ text]  allergytime [ time] 
SELECT MIN(lab.labresult) FROM lab WHERE lab.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '018-81471')) AND lab.labname = 'paco2' AND STRFTIME('%y', lab.labresulttime) <= '2104' GROUP BY STRFTIME('%y-%m-%d', lab.labresulttime)