190. The rental value of a place of business or of premises is established on the basis of the gross annual rent that would most likely be obtained therefrom under a lease renewable from year to year, according to market conditions, including real estate taxes and the operating expenses of the unit of assessment, or, as the case may be, of that part of the unit representing the place of business or the premises, but not taking into account the price or the value of services other than those connected with the immoveable.