The fees of county officers shall be regulated by law. In counties or cities having a population of seventy-five thousand or more, the Clerks of the respective Courts thereof (except the Clerk of the City Court), the Marshals, the Sheriffs and the Jailers, shall be paid out of the State Treasury, by salary to be fixed by law, the salaries of said officers and of their deputies and necessary office expenses not to exceed seventy-five per centum of the fees collected by said officers, respectively, and paid into the Treasury.