It seems that the most conservative estimate puts the total number of new partakers from the late 1880's to present at about 100k easily. The early Bible Students from 1879 to 1935 must be included, since the Bible Students were chosen by Jesus in 1919 (aherrmbollox)...something the Watchtower teaches.
That leaves barely any room for all the thousands from pentecost 33CE to 1879.
Clearly the 144k literal interpretation is a sham. (The only way out of it is for the Watchtower to assert that not all partakers are genuine, that only about 50% are genuine as someone said earlier, but would they put that in print?? hardly.)
Their 144k interpretation will have to be dumped before too long if the number of partakers keeps increasing at the rate it has in the last two years. It all depends on that.