what is the maximum number of patients diagnosed with ami inferior wall, init daily until 4 years ago?
select max(t1.c1) from ( select count( distinct diagnoses_icd.hadm_id ) as c1 from diagnoses_icd where diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = 'ami inferior wall, init' ) and datetime(diagnoses_icd.charttime) <= datetime(current_time,'-4 year') group by strftime('%y-%m-%d',diagnoses_icd.charttime) ) as t1