###HUMAN: provide the number of patients whose year of death is less than or equal to 2174 and drug code is osel75?, ###ASSISTANT: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN prescriptions ON demographic.hadm_id = prescriptions.hadm_id WHERE demographic.dod_year <= "2174.0" AND prescriptions.formulary_drug_cd = "OSEL75"