อายุขั้นต่ำของผู้ป่วยที่มีประกันเอกชนและปีที่เสียชีวิตน้อยกว่า 2122 คือเท่าใด ไม่จำเป็นต้องใช้ตารางทั้งหมด
what is minimum age of patients whose insurance is private and year of death is less than 2122?It is not neccessary to use all the tables.
 demographic:  subject_id [ text]  hadm_id [ text]  name [ text]  marital_status [ text]  age [ text]  dob [ text]  gender [ text]  language [ text]  religion [ text]  admission_type [ text]  days_stay [ text]  insurance [ text]  ethnicity [ text]  expire_flag [ text]  admission_location [ text]  discharge_location [ text]  diagnosis [ text]  dod [ text]  dob_year [ text]  dod_year [ text]  admittime [ text]  dischtime [ text]  admityear [ text] 
SELECT MIN(demographic.age) FROM demographic WHERE demographic.insurance = "Private" AND demographic.dod_year < "2122.0"