All legislative powers of the city shall be vested in a board of aldermen consisting of five (5) aldermen who shall be elected as hereinafter provided and who shall hold office for a term of four (4) years or until their successors are elected and qualified. Effective as of the term beginning in January 2006, the regular term of aldermen shall expire on the second Thursday in December of each regular city election year, at which time the newly elected board of aldermen shall take office. (Acts 1951, Ch. 539, § 7; Res. of 3-18-65; Res. No. 16-81, § 1, 4-16-81; Res. No. 05-4, § 1, 1-20-05)