instruction: what is the number of patients whose admission year is less than 2162 and procedure long title is percutaneous [endoscopic] gastrojejunostomy?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.admityear < "2162" AND procedures.long_title = "Percutaneous [endoscopic] gastrojejunostomy"