instruction: how many patients until 2103 received a sputum, tracheal specimen microbiology test?
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) <= '2103')