No to-hit, damage, DV increases at L16 weapon skill

[Grond]

For every weapon type I've tested (unarmed, daggers, swords (2H), polearms (2H), staves), there is no increase in to-hit, damage, or DV when going from level 15 to level 16. My suspicion is that levels 1-15 have manually entered bonuses, and it switches to some formula for later levels.