The engineer shall also classify all lots, tracts, lands, and other property according to the benefit that each may receive from such drainage improvement, and the lots, tracts, and lands receiving the greatest percentage of benefits shall be classified at one hundred, those receiving a less percentage of benefit at such less number as its benefit may determine. The property of public and private corporations may be classified in a list by themselves, each according to the relation its total benefits bear to the total benefit in the district.