ch require premium or other payments by him on the basis 22 of earnings and other remuneration earned by persons engaged in the 23 furtherance of his enterprise or enterprises, the promptness and 24 completeness of such reports as he has filed on accidents and claims, 25 and such other factors as may be relevant to the appraisal of the 26 insured or proposed insured as a risk in whole. 27 A premiu