Is there anything to support an estimate of 30 made guys in Detroit other than the estimate itself?

i.e., are there any signs of activity--busts, murders, etc.?

At the risk of starting another never-ending mudslinging contest, the Feds estimate Chicago has less than 30 made guys right now.

While I suppose the idea of Detroit having more guys than Chicago is not impossible, I can't think of any reason, from documented history to population demographics, that it would be so.

All indicators in fact would point to Detroit having a mere fraction of what Chicago has.