Nï ka cikke guïïrɣic, këye cɔl exponetial functions model taan yenneke riir ɛɛ thööŋ na gɛr yen ni këye cɔl independent variable ye nuɔn tokde proportional change bɛi ( citmaande, percentage ɛɛ rɔt cuɔr nhial ku ye dhupiny) niye kecɔl dependent variable.