(red = mistake, blue = better)
Yes, all verbs have to be at the end. However, often you would try to use the same verb for the listed things and then put it at the end only once, like:
in einer Bevölkerung, in der 55% Mittelschichtler, 20% Fabrikarbeiter und 10% türkisch waren.
I know its off topic but I noticed you corrected angelofmusic 101´s spelling of Bevölkerung and türkisch. Is the `e´ (bevoelkerung/tuerkish)not allowed in modern day German anymore? Some people may not have access to or know how to change their keyboard layout. I´m sorry to go off topic I was just curious.