instruction: when was patient 67468 first diagnosed in 2105 with pressure ulcer, stage iv?
response: SELECT diagnoses_icd.charttime FROM diagnoses_icd WHERE diagnoses_icd.icd9_code = (SELECT d_icd_diagnoses.icd9_code FROM d_icd_diagnoses WHERE d_icd_diagnoses.short_title = 'pressure ulcer, stage iv') AND diagnoses_icd.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 67468) AND STRFTIME('%y', diagnoses_icd.charttime) = '2105' ORDER BY diagnoses_icd.charttime LIMIT 1