$ in PWRD / $ in Vault. Higher utilisation generates higher Vault yields. When utilisation goes higher than 80%, Vault holders are compensated more generously and could generate almost twice the yield they would if they had their assets in the same strategies, exposed to the same risk, but outside of the Gro protocol. See the following for more details.
Vault total yields = Vault deposit yields + (30% + 3/8*Utilisation) * PWRD deposit yields
Vault total yields = Vault deposit yields + [60% + 2(Utilisation - 80%)] * PWRD deposit yields