Coupon policies issued or delivered in this state shall be subject to the following provisions:

(1) No detachable coupons or certificates or passbooks may be used. No other device may be used which tends to emphasize the periodic endowment benefits or which tends to create the impression that the endowments represent interest earnings or anything other than benefits which have been purchased by part of the policyholder's premium payments.

(2) Each endowment benefit must have a fixed maturity date and payment of the endowment benefit shall not be contingent upon the payment of any premium becoming due on or after such maturity date.

(3) The endowment benefits must be expressed in dollar amounts rather than as percentages of other quantities or in other ways, both in the policy itself and in the sale thereof.

(4) A separate premium for the periodic endowment benefits must be shown in the policy adjacent to the rest of the policy premium information and must be given the same emphasis in the policy and in the sale thereof as that given the rest of the policy premium information. This premium shall be calculated with mortality, interest and expense factors which are consistent with those for the basic policy premium.