instruction: count the number of patients who have received a microbiological sputum, tracheal specimen test until 2104.
response: SELECT COUNT(DISTINCT patient.uniquepid) FROM patient WHERE patient.patientunitstayid IN (SELECT microlab.patientunitstayid FROM microlab WHERE microlab.culturesite = 'sputum, tracheal specimen' AND STRFTIME('%y', microlab.culturetakentime) <= '2104')