Every person doing business within this State and engaging in the business of selling alcoholic liquors, except distillers thereof, for the privilege of carrying on such business shall, in addition to the license tax provided in § 12-33-210, be subject to the further payment of a license tax which shall be measured and graduated in accordance with the volume of sales of such business. There shall be levied, assessed, collected and paid in respect to the alcoholic liquors referred to in this chapter twelve cents upon each eight ounces or a fractional quantity thereof. Provided, that for alcoholic liquors offered for sale in metric size containers there shall be levied, assessed, collected and paid a tax at the rate of fifty and seven-tenths cents per liter.