A person aggrieved by the decision of the assessors may appeal to the Board of Tax Appeals on or before the 19th day of June or within 14 days after the date of mailing of notice, under section 90 of this Charter, by filing with the Chief Administrative Officer of said City a written notice of appeal. The grounds upon which such appeal is based shall therein be briefly set forth; such person shall also notify said assessors in writing of the appeal. The Board of Tax Appeals shall consist of seven residents of the City of Burlington, two of whom shall be real estate professionals and five of whom shall not be required to be real estate professionals. The City Council shall also appoint three of its members to serve as additional members of the Board of Tax Appeals for the purpose of hearing and deciding appeals which arise immediately following implementation of a citywide reappraisal.