According to their doctrine there were tens of thousands in the first century. Then over the last 20 centuries there were an unknown number chosen some of the Bible translators and other Christians who were burned and such for their faith.
Then in modern times even my grandfathers times around the time of WW2, most of the congregations were full of those who claimed a heavenly hope. My parents grew up in congregations that were full of so called anointed older ones.
then slowly after the 1950s there were less and less anointed ones and you started to get older ones who had an earthly hope which was unusual.
the numbers do not add up