อายุขั้นต่ำของคนไข้ที่มีเชื้อชาติเป็นคนผิวขาวและเข้ารับการรักษาก่อนปี 2121 คือเท่าใด ไม่จำเป็นต้องใช้ตารางทั้งหมด
What is the minimum age of patients whose ethnicity is white and were admitted before the year 2121?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.ethnicity = "WHITE" AND demographic.admityear >= "2121"