Before assuming the duties of his office, each deputy county officer shall take and subscribe the oath of office prescribed by the constitution for county officers. The board of county commissioners may cause to be bonded the deputy or deputies of the various county officials who are not otherwise required to be bonded. These bonds shall be in amounts fixed by the board of county commissioners in a sum equal to twenty percent of the public money handled during the preceding fiscal year and conditioned for the faithful performance of his duties, but in no event shall the amount be greater than the maximum prescribed by law for the appropriate elected officer. The bonds shall be executed by corporate surety companies authorized to do business in this state and the premiums shall be paid from the county general fund. Deputy county officers may be individually bonded or included within the coverage under any schedule or blanket corporate surety bond procured by the board of county commissioners.