Be it further enacted, that all the sinking funds of the city may be invested by the city manager, by and with the consent of the City Council, in bonds of the United States, of the State of Tennessee, or of the City of Crossville at the best price obtainable. (As amended by Priv. Acts 1972, ch. 416, sec. 11, Priv. Acts 1995, ch. 55, sec. 2, and Priv. Acts 2014, ch. 55, sec. 1)