Not a clue.
I teach school groups from all over the state, they show up, get a class on primitive tools and weapons and get to throw a dart with an atlatl, use a sling with tennis balls and toss a throwing stick and get a basic class on how to fight with a war club. Most are around 9 or 10 but some are PreK.
If they show up, and there's time in the schedule, I'll show all the kids how to do it. The really young kids are usually with the parents who are helping the teachers ride herd on the groups.
Some do lots better than others, I had a 6 year old and his 5 year old brother start tossing a tennis ball back and forth one time. Not only were they throwing the ball to each other about 25 meters or so away, they didn't have to move to catch it and they did catch the ball.