Is there a sutta about how many ariyas there were at the buddhas time?
Or about how many percent of his followers attained at least sotapatti at the buddhas time?
All the best.
I don’t myself. But tradition say in the region or sangha of Ananda, Mahakassapa , the first council it’s 500 Arahants. But nothing is said about other regions. Where Buddha preached. Just that many enter the path to enlightenment or even attainted sainthood.