50 MILLION babies have been slaughtered so it makes sense, I assume he has simply figured out which percentage of the population would correspond with each profession.
It is even more staggering to consider that statistically about half of those aborted were female and many of them (by my calculation 15 million or so women would now be adults) would now be having children of their own.
Not all of these babies would have made it to age ten, but even so, point is the loss must be indeed compounded to exceed, what 70 million. Why else have the borders been lowered, except to replace the missing hands?