Imikorere yo kwisiga ni nziza.Kuberako ikibaho gikonjesha gifite imiterere yihariye, ingano ya 60 ~ 70% muburyo bwimpapuro zirimo ubusa, bityo ifite imikorere myiza yo gukurura ihungabana, kandi irashobora kwirinda kugongana ningaruka zingingo zipakira.