As used in this chapter:
“County offices” or “county officers” means the elected or appointed public officers of the respective counties and includes county council members, Levy Court Commissioners, clerks of the peace, members of the boards of assessment, receivers of taxes and county treasurers, collectors of delinquent taxes, registers of wills, sheriffs, recorders, coroners and any other officer, board, commission, department or agency (other than a court or judge) whose jurisdiction is limited to a single county; provided, however, that the Prothonotaries of New Castle County, Kent County and Sussex County shall not be considered to be county offices.