with R1 as
(select distinct ci.pre_enquete_village.region_niv1 as ABSCISSE,strate,libel_engin  as GROUPE,
count(no_menage)*txa as total from
ci.pre_enquete_village  inner join ci.liste_site using (no_enquete)
inner join ci.calcul_txa using (strate)
inner join ci.v_liste_menage using (no_site)
inner join ci.v_menage_engin using(no_menage)
group by ci.pre_enquete_village.region_niv1,libel_engin,txa,strate order by total desc)
select distinct ABSCISSE,GROUPE,100*sum(total)/som_total as total from
 R1 inner join (select distinct ABSCISSE,sum(total) as som_total from R1 group by ABSCISSE) R2 using (ABSCISSE)
group by abscisse,groupe,som_total
 order by ABSCISSE