what is the yearly minimum amount of ultrafiltrate ultrafiltrate that patient 20034 had until 12/21/2105?
select min(outputevents.value) from outputevents where outputevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 20034 ) ) and outputevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'ultrafiltrate ultrafiltrate' and d_items.linksto = 'outputevents' ) and strftime('%y-%m-%d',outputevents.charttime) <= '2105-12-21' group by strftime('%y',outputevents.charttime)