The bond shall be in the amount of fifty thousand dollars ($50,000) in counties with a population of less than fifteen thousand (15,000), and one hundred thousand dollars ($100,000) in counties with a population of fifteen thousand (15,000) or more, according to the 2010 federal census or any subsequent federal census, or in a greater sum as the county legislative body may determine, payable to the state of Tennessee, conditioned on the true and faithful discharge of the duties of the office.