Imijyi izibasirwa cyane ni imijyi yari isanzwe izwiho kuba igicumbi cy’inganda, ariko magingo aya izo nganda zikaba zitakihabarizwa kandi nta bindi bifatika byazisimbuye, bishobora guha akazi urubyiruko rwayivukiyemo.

Nibura mu 2100, imijyi mito n’uduce ibihumbi 15 mu bihumbi 25 byakoreweho ubushakashatsi, izaba ifite igabanuka rikabije ry’abaturage. Imijyi izibasirwa cyane irimo iri muri Leta za Michigan, Ohio, Missouri na Alabama.

Muri rusange, byitezwe ko abaturage ba Amerika bazatangira kugabanuka mu 2080, ariko bikazarushaho kujya ahabi mu myaka 20 izakurikiraho, ubwo hejuru ya 50% by’imijyi mito n’uduce two muri icyo gihugu cya mbere mu kugira ubukungu bunini ku Isi, izaba ihanganye n’ikibazo cy’igabanuka ry’abaturage.

Imijyi mito yahozemo inganda izatakaza abaturage benshi mu myaka 75 iri imbere