This question has been asked to Srila Prabhupada as early as 1968. Let us see how Srila Prabhupada answers it:
Guest: How many other people are there on this planet who have made as much spiritual progress as you have?
Prabhupada: Many. But not many, but there are many also. But there is no statistics in my possession. But... The formula is that what is the use of taking statistics how many there are? Why don't you become one of them? [laughter] Why you are wasting time in that way? These are not very intellectual questions. You just try to become enlightened. What is use of who is enlightened or not? You try to be enlightened. That's all.
You are going somewhere, purchasing the plane ticket. Do you ask, "How many tickets you have sold?" Huh? What is the use of? You just purchase your ticket and get on the airplane and go. [laughter] Don't waste your valuable time in that way. If you are serious, just purchase ticket and get on the airplane and pass on. That's all.
(Bhagavad-gita 2.40–45 – December 13, 1968, Los Angeles)