§ 247. Racing zones. There are hereby created two racing zones to be known as the first zone and the second zone. The first zone shall include all of the counties in the first, second, ninth, tenth, eleventh and twelfth judicial districts. The second zone shall include all the other counties of the state. Not more than six corporations shall hereafter be licensed by the commission or franchised by the state to conduct a race course or race meeting for running races or steeplechases at which pari-mutuel betting shall be authorized within the first zone, and not more than three of such corporations shall hereafter be so licensed within the second zone. The commission shall not hereafter approve the incorporation of such a corporation for conducting a race course or race meeting within the second zone if the location of the proposed race course of such corporation is within seventy-five miles of the race course of another such corporation.