What's happening with the labels?

In PTC Mathcad Questions we still have only, for example, 7 labels for Algebra & Geometry, and 2 labels for Chemical Engineering. We had separate forums for both of those topics, and they certainly had more than 7 and 2 threads in them. A lot more. Hundreds. We now have 169,438 posts (it's not clear if that's actually posts, or threads, but threads would be a more useful number), which were sorted into categories. I thought the labels were going to be assigned based on the forums the threads came from. Or was that just wishful thinking on my part?