Thank you for the link to the paper. I wasn't able to find in the paper any basic data, only derived coefficients. The map is the same, including the "maximal extent" which happened only at the few years the territories were occupied during WWI. The big movements of big amount of people over the territories during the turbulent history are also somehow not addressed. There's a unique history behind each settlement, not taking that in the consideration or not showing what you actually did I believe any conclusion can be generated. I still question some premises and the execution of the paper.