Is the €134k/mo figure including all corporate sponsors? Approximating that as one developer salary per month then what they've continued to accomplish is still very impressive.
It does appear that the majority of top contributors are from European countries but overall pretty diverse: China, Australia, New Zealand, Russia, Brazil, Egypt are represented as well.
That said, if I revised my comment to say two developer salaries per month, or 3, 4, etc. it is still impressive in my view.