In Project Web App: Where to find the Current Max Units of an Enterprise Resource using Rest-API?

I'm trying to find the Current Max. Units of an Enterprise Resource in the Rest-API of Project Web App. I can't find it in the ProjectServer/EnterpriseResources('ID') endpoint. Also i can't find it in Assignments, BaseCalendar, CostRateTables etc within the EnterpriseResource. Does anyone know, where i can find it?