I've seen two surveys in the past week, one where Detroit ranked second in IT job growth and this one by Forbes that ranked Detroit 9th.
https://www.forbes.com/sites/joelkotkin/2017/03/16/technolog...
Detroit didn't rank here because the cities population is below a million. But with the suburbs Detroit metro is 5 million and I believe that doesn't include Ann Arbor which just ranked as a top startup hub. So this particular survey is a little misleading.