Each public utility, its agents, servants or employees, serving the consumers in the city shall keep a separate record of the physical properties, accounts, income and disbursements for that portion of its business serving consumers within the corporate limits of the city, and shall not include therein any accounts, records or property that may be used to serve consumers in any city, town or village that may be hereafter incorporated under the laws of the state.
(1964 Code, § 30-2)