instruction: when patient 28966 last got surgery in 2100.
response: SELECT procedures_icd.charttime FROM procedures_icd WHERE procedures_icd.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 28966) AND STRFTIME('%y', procedures_icd.charttime) = '2100' ORDER BY procedures_icd.charttime DESC LIMIT 1