Upon petition of at least ten percent of those voting in the last school election at which school board members were elected or one hundred voters, whichever is greater, filed with the board, the question of dissolving a seven-director district shall be submitted to the voters at a municipal election and if a majority of the voters voting thereon vote in favor of dissolution, the district shall be dissolved and the same territory included in the district may be annexed as provided by section 162.081.