instruction: until 12 months ago what was the first value of the total bilirubin-lab test of patient 006-21388?
response: SELECT 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 = '006-21388')) AND lab.labname = 'total bilirubin' AND DATETIME(lab.labresulttime) <= DATETIME(CURRENT_TIME(), '-12 month') ORDER BY lab.labresulttime LIMIT 1