The factors computed pursuant to sections 77-2734.05 to 77-2734.15 shall be adjusted in the following situations:
(1) The sales factor shall include the income from intangibles such as interest, royalties, or dividends and the net income from gains on the sale of intangibles;
(2) Except as provided in subdivision (1) of this section, the factors shall not include in the denominator any amount that cannot be assigned to a numerator because of the inability to reasonably identify the location of an income-producing activity;
(3) The factors shall not include any amount that was eliminated as an intercompany transaction;
(4) The factors shall not include any property, payroll, or sales that are a part of the production of income that is not subject to apportionment;
(5) The property factor shall include the intangible drilling costs incurred on property that is owned or rented and used during the tax period; and
(6) The property factor of a corporation or unitary business engaged in the exploration and extraction of natural resources shall include undeveloped mineral leases and royalty payments on producing leases, except that those mineral leases determined not suitable for production shall not be included in the property factor.