instruction: how many patients are diagnosed with primary disease atrial septal defect mitral valve replacement repair atrial-septal defect/sda and are born before 2111?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic WHERE demographic.diagnosis = "ATRIAL SEPTAL DEFECT\MITRAL VALVE REPLACEMENT;REPAIR ATRIAL-SEPTAL DEFECT/SDA" AND demographic.dob_year < "2111"