The City Manager shall be chosen by the council solely on the basis of his/her executive and administrative qualifications with special reference to his/her actual experience in, or his/her knowledge of, accepted practice in respect to the duties of his/her office as hereinafter set forth. At the time of his/her employment, he/she need not be a resident of the City or State, but during his/her tenure of office he/she shall reside within the City unless specifically excused from doing so by the council.