The rate of the tax imposed shall be one-half of one percent of the selling price or value of the article used, as the case may be. If Stevens County should impose a sales or use tax equal to or greater than the tax imposed by this section, the County shall receive fifteen percent of the tax imposed on the City. If the rate imposed by the County is less than that imposed by the City, the County shall receive fifteen percent of the rate of tax imposed on the County.