what percentile is the calculated total co2 value of 32.0 in the same age group as patient 25847 during the first hospital encounter?
select distinct t1.c1 from ( select labevents.valuenum, percent_rank() over ( order by labevents.valuenum ) as c1 from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'calculated total co2' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.age = ( select admissions.age from admissions where admissions.subject_id = 25847 and admissions.dischtime is not null order by admissions.admittime asc limit 1 ) ) ) as t1 where t1.valuenum = 32.0