Section 5.7.  Declaration of vacancy in elective office.
   Any elective city office shall be declared vacant by the council before the expiration of the term of such office:
   (a)   For any reason specified by statute or by this Charter as creating a vacancy in office;
   (b)   If no person is elected to, or qualified for the office at the election at which such office is to be filled;
   (c)   If the officer shall be found guilty by a competent tribunal of any act constituting misconduct in office under the provisions of this Charter;
   (d)   In the case of any member of the council, if such officer shall miss four consecutive regular meetings of the council or twenty-five percent of such meetings in any fiscal year of the city, unless such absence shall be excused by the council and the reason therefor entered in its proceedings at the time of each absence;
   (e)   If the officer is removed from office by the council in accordance with the provisions of Section 5.9.