what is the minimum number of yearly diagnosed cases of abdom aortic aneurysm?
select min(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 = 'abdom aortic aneurysm' ) group by strftime('%y',diagnoses_icd.charttime) ) as t1