If the Board of Aldermen determines that the public health, welfare, and safety are adequately served and protected in view of the foregoing criteria then it shall grant the application and the permit shall be issued forthwith; but if the Board finds in the negative as to any of the stated criteria, the conditional use permit shall be denied. Provided, however, that if at least twenty-five percent (25%) of the persons entitled to notice under the terms of Subsection (B)(3) of this Section, above, protest the granting of such application in a writing filed with the Zoning Enforcement Officer no later than one (1) day before the date of the public hearing thereon, such application shall not be granted unless two-thirds (2/3) of all the members of the Board of Aldermen vote in favor of its issuance.