When the reported value of `RentalUnitsInAdministrationOrManaged` is equal to `Ja` then `NumberOfRentalUnitsManagedByOthers` and/or `NumberOfRentalUnitsManagedForOthers` MUST exist once.
When the reported value of `RentalUnitsInAdministrationOrManaged` is equal to `Nee` then `NumberOfRentalUnitsManagedByOthers` MUST NOT be reported.
When the reported value of `RentalUnitsInAdministrationOrManaged` is equal to `Nee` then `NumberOfRentalUnitsManagedForOthers` MUST NOT be reported.
`NumberOfRentalUnitsManagedByOthers` MUST be greater than 0.
`NumberOfRentalUnitsManagedForOthers` MUST be greater than 0.
`RentalUnitsInAdministrationOrManaged` MUST exist at least once.