2017 Memorial Partakers
From my experience back during the 1970s to 1990, the largest number and any increase of anointed has always been in and come from the United States.
The largest number of the "remnant" was associated with Russell in the U.S. in the 1800s. The same was true during the time of Rutherford. From what I remember from reports and discussions with anointed elders during my time, America was still where "Jehovah" had the largest number of anointed.
My educated guess is that the increase today is no different. The idea that recent "third world country converts" are responsible for the increase is unfounded, without backup data, and likely based on cultural and perhaps even racial prejudice that the Watchtower takes advantage of.
There is more a feeling of entitlement in the American culture than in other parts of Western society, not to mention other parts of the world. This would account for increasing to remain popular and steady in the U.S. Since there is no new specific data to go on at present and all we have is the past data to rely on, there is no reason to assume that the American trend has somehow suddenly or will ever change, especially since the culture definitely has not.
While this is just my hypothetical take, I would bet good money that the increase in Memorial Partakers is still in the U.S., and perhaps even among younger white men in positions of privilege of whom the current members of the Governing Body might even find threatening. This would account for the reason of stating these "new" partakers may have "mental issues," for they will surely outlive them and be forced to revise, correct, and even dismiss the current Governing Body's doctrines as foolishness. To avoid others from listening to any of them now, the Governing Body is painting these younger men today as deranged. That is what I would say is really happening.