Who knows three hundred thirty one?
אחד ושלושים ושלוש מאות - מי יודע?
The traditional Passover song "Echad - mi yodeya" implies a possible presupposition that there is a Jewish significance to be found for each natural number. Accordingly, there is an ongoing series on Mi Yodeya that is attempting to unearth significant Judaism facts about each number, in sequence.
What significant Judaism facts are there about the number 331? The more significant within Judaism and the more intrinsically dependent on the value 331, the stronger the answer. Please include sources for your information wherever possible, as with all other answers on this site.
I'm asking these questions, not to get lazy gematria answers, but to provide a haven for those who know numbers in Judaism, and to fire the imagination of those who want to learn more.