How many years did Stalin say they were behind advanced countries?

We have fallen behind the advanced countries by fifty to a hundred years. We must close that gap in ten years. Either we do this or we'll be crushed. This is what our obligations before the workers and peasants of the USSR dictate to us.

I'm quoting Stalin here, so please don't demonetize me (It's fair use smh)

We have fallen behind the advanced countries by fifty to a hundred years. We must close that gap in ten years. Either we do this or we'll be crushed. This is what our obligations before the workers and peasants of the USSR dictate to us.

sense of self-interest