21. Where he is not paid exclusively on a percentage basis, a damage insurance representative must charge and accept remuneration or compensation that is fair and reasonable given the services rendered. In particular, he must take into account the following factors in determining his remuneration or compensation:
(1) his experience;
(2) the time devoted to the matter;
(3) the difficulty of the problem submitted;
(4) the importance of the matter;
(5) the responsibility assumed;
(6) the provision of unusual services or services requiring exceptional competence or speed;
(7) the result obtained.