disposition of surplus.] The void indebtedness mentioned in Section 6-6-11 N.M. Stat. Ann. shall remain valid to the extent and for the sole purpose of receiving any money which may afterwards be collected and belongs to the current year when they were contracted, and the collection thereof, when made, shall be distributed pro rata among the creditors having the void indebtedness, and in the event all of the valid and void indebtedness of any current year are paid in full and there is money for that current year remaining, the sum shall be converted into the fund for the next succeeding current year.