what is the yearly minimum amount of immunoglobulin a of patient 15209 since 2100?
select min(labevents.valuenum) from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 15209 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'immunoglobulin a' ) and strftime('%y',labevents.charttime) >= '2100' group by strftime('%y',labevents.charttime)