ผู้ป่วยอายุน้อยกว่า 70 ปีที่เข้ารักษาในโรงพยาบาลก่อนปี 2180 มีกี่ราย ไม่จำเป็นต้องใช้ตารางทั้งหมด
what is the number of patients less than 70 years who were admitted to hospital before 2180?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 COUNT(DISTINCT demographic.subject_id) FROM demographic WHERE demographic.age < "70" AND demographic.admityear < "2180"