บอกจำนวนผู้ป่วยเข้าโรงพยาบาลฉุกเฉินอายุต่ำกว่า 67 ปี ไม่จำเป็นต้องใช้ทุกโต๊ะ
tell me the number of urgent hospital admission patients aged less than 67 years.It is not neccessary to use all the tables.
 procedures:  subject_id [ text]  hadm_id [ text]  icd9_code [ text]  short_title [ text]  long_title [ text] 
SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic WHERE demographic.admission_type = "URGENT" AND demographic.age < "67"