Note that 0.04 cm³ is the volume of a cube with side length ≈ 0.34 cm, so in the way we usually think of scale, the average was about ⅓ of the approved maximum.
Yes, but its about 4% of the total maximum volume, not a third. Its just that the "sides" of the cube are about a third of the maximum. Like, if it had a constant density, it'd be 4% of the mass of the maximum, not a third.