If your parents have fought with each other all your life, what are the chances of having depression?

At risk: I hear in your question that you've been deeply impacted by the yelling. Have you yet tried any form of psychotherapy? Typically, the optimal combination of things to treat emotional issues such as depression is medication (which, on your best day, is supposed to take the edge off symptoms) but the real gruntwork takes place in psychotherapist's consulting room.

Elevated risk: Recurrent stressors that include familial strife are a risk factor for depression in children, adolescents, and adults. Some Core signs of depression include recurrent low mood, loss of interest in enjoyable activities and important necessary daily activities, helplessness/hopelessness, and problems with sleep. If a concern recommend further evaluation by your doctor to discuss options

There are: correlations between dysfunctional family-of-origin dynamics and later psychiatric/psychological disorders--depression and anxiety being the top two, in frequency. Its hard to quantify this because there are many reasons parents fight, even some good ones. See a psychologist or MFT for a deeper look-see.