indicate the monthly average volume of jackson pratt #1 that patient 73693 has had since 1869 days ago.
select avg(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 = 73693 ) ) and outputevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'jackson pratt #1' and d_items.linksto = 'outputevents' ) and datetime(outputevents.charttime) >= datetime(current_time,'-1869 day') group by strftime('%y-%m',outputevents.charttime)