what is the yearly minimum value of patient 61003's iron since 12/2102?
select min(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 61003 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'iron' ) and strftime('%y-%m',labevents.charttime) >= '2102-12' group by strftime('%y',labevents.charttime)