Also, possibly consider using a different source. The entire East Rand (Ekurhuleni) seems to have been merged into Johanneburg, when they are very much separate cities and are run by a completely different municipality. Evaton, which is run by Joburg Municipality, is shown as being separate from Joburg though. I understand that you qualified the quiz as being linked to the source, I just don't think that the source is particularly good. Nice concept though!