instruction: what is the last time that patient 035-4312 was prescribed lactated ringers injection 1,000 ml since 180 months ago?
response: SELECT medication.drugstarttime FROM medication WHERE medication.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '035-4312')) AND medication.drugname = 'lactated ringers injection 1,000 ml' AND DATETIME(medication.drugstarttime) >= DATETIME(CURRENT_TIME(), '-180 month') ORDER BY medication.drugstarttime DESC LIMIT 1