Take with a grain of salt.

its 'per capita' allegedly.... they need to average it out to make it more comparable between states. also the title is nonsense.

And OP never indicated much, as to how he built the map.

For example, PA is listed as low amounts of permits...but I think thats because there are simply enough older homes available, that new construction is less desirable.

IF thats what OP did, Im assuming he calculated; Permits/residents

But its unclear from the map title alone. And Im not going to comb through their links, because the onus should be on them to clarify their methodology.

If they were mapping percentages of permits/rejections That would be a bit more fitting of the title. But ultimately more information is needed.