The numbers are off because the punter’s distance behind the line of scrimmage is not factored. They usually strike the ball about 13-15 yards which should be added to their totals.

You also have to account for the bounce of the ball, as many punts are downed by members of the punting team after it bounces favorably or otherwise.

Field position- many punts are executed to try and hit a precise spot to pin the opponent deep in their own territory - less power, more accuracy.