บอกราคาโรงพยาบาลโดยเฉลี่ยเมื่อมีโรคหลอดเลือดหัวใจถึงปี 2104 หรือไม่ไม่จำเป็นต้องใช้ตารางทั้งหมด
tell me the average hospital cost when there is coronary artery disease until 2104?It is not neccessary to use all the tables.
 vitalperiodic:  vitalperiodicid [ number]  patientunitstayid [ number]  temperature [ number]  sao2 [ number]  heartrate [ number]  respiration [ number]  systemicsystolic [ number]  systemicdiastolic [ number]  systemicmean [ number]  observationtime [ time] 
SELECT AVG(t1.c1) FROM (SELECT SUM(cost.cost) AS c1 FROM cost WHERE cost.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.patientunitstayid IN (SELECT diagnosis.patientunitstayid FROM diagnosis WHERE diagnosis.diagnosisname = 'coronary artery disease')) AND STRFTIME('%y', cost.chargetime) <= '2104' GROUP BY cost.patienthealthsystemstayid) AS t1