var cbInfos = from c in dsTransVolumes.Tables[0].AsEnumerable()
                       join r in dsAssets.Tables[0].AsEnumerable() on
                       c.Field<string>("ID") equals r.Field<string>("ID")
                       select new
                       {
                           AsseTurnover = c.Field<decimal>("TransVolumes") / r.Field<decimal>("Assets"),
                           ID = c.Field<string>("ID"),
                           TransVolumes = c.Field<decimal>("TransVolumes"),
                           Assets = r.Field<decimal>("Assets")

                       };