287.021.  Sheriffs and deputy sheriffs to be covered by workers' compensation — average earnings defined. — 1.  As used in this chapter, the term "employee" includes a sheriff or deputy sheriff and the term "employer" includes a county in regard to a sheriff or deputy sheriff.

  2.  Each county shall provide workers' compensation insurance in an insurance group licensed to write workers' compensation insurance in this state, or a city also recognized as a county may have at all times sufficient self-insurance coverage, so that all sheriffs and deputy sheriffs in the county or self-insured city recognized as a county will be covered.

  3.  The "average earnings" of a sheriff or deputy sheriff is his annual salary, or fourteen dollars per day, whichever is greater.

  4.  The provisions of this section shall not be construed to create any tort liability upon a county or to impose any duty upon a county other than complying with this chapter in relation to sheriffs and deputy sheriffs.