There is imposed upon the qualified heir an additional inheritance tax if, within ten years after the decedent‘s death and before the death of the qualified heir, the qualified heir disposes of, other than to a member of the family, any interest in qualified real property for which an election under section 450B.2 was made or ceases to use for the qualified use the qualified real property for which an election under section 450B.2 was made as prescribed in section 2032A(c) of the Internal Revenue Code. The additional inheritance tax shall be the amount computed under section 450B.5 and shall be due six months after the date of the disposition or cessation of qualified use referred to in this section. The amount of the additional inheritance tax shall accrue interest at the rate of ten percent per year from nine months after the decedent’s death to the due date of the tax. The tax shall be paid to the department of revenue and shall be deposited into the general fund of the state. Taxes not paid within the time prescribed in this section shall draw interest at the rate of ten percent per annum until paid. There shall not be an additional inheritance tax if the disposition or cessation occurs ten years or more after the decedent’s death.