What is seems you're looking for is when 'other sheep' started to be gathered
So just to clarify, in WT theory at Pentecost 33CE when the spirit was poured out, all there were of the annointed. And over time, as they preached to the gentiles and Jews some newbies would have become annointed and some of the other sheep and not annointed.
But I'm sure I read somewhere in a WT that basically the first century christians were thought to be of the annointed. 5,000 were added at Pentecost and another 4,000 soon after according to the Bible. So that's over 5% of the annointed right there. According to the footnote in the WT Online library on Acts 21:20 after the words 'thousands' it says “myriads; tens of thousands.”
I'm looking into how many christians died in the first few centuries, and just now found this quote on JW Facts from the WT:
"Diocletian assumed the crown A.D. 284. At first he seemed friendly to the Christians, but in the year 303 he gave in to persuasion and opened the tenth persecution, probably the most ferocious of all. Suffocation by smoke, forcible drinking of melted lead, mass drownings and burnings, breaking on the rack of men and women alike ran the empire with blood. In a single month 17,000 were slain. In the province of Egypt alone, 144,000 such professed Christians died by violence in the course of this persecution, in addition to another 700,000 who died as a result of fatigues encountered in banishment or under enforced public works." Watchtower 1951 September 1 p.518
Which is very helpful (gawd bless JW Facts).
Now that's a vast number. So at least some of the annointed would have died in that time, so if the annonited had existed since 33CE and if the memorial figures were right in the 1930s....
Nah. Doesn't stack up does it?
Oh well, that's a bit more of my faith crumbling right there.