379.720.  Deficiency how made up — net premium and deposit defined. — 1.  If at any time the amounts on hand are less than the requirements of sections 379.700 and 379.710, the subscribers or their attorney for them shall make up the deficiency.

  2.  Where funds other than those which have accrued from premiums or deposits of subscribers are supplied to make up a deficiency as herein provided for they shall be deposited and held for the benefit of subscribers under such terms and conditions as the director of the department of commerce and insurance may require so long as the deficiency exists, thereafter to be returned to the depositors.

  3.  "Net premiums" or "deposits" as used in this law shall be construed to mean the advance premiums or deposits made by subscribers after deducting therefrom the amount for expenses specifically provided in the subscriber's agreement.