The unearned premium reserve of a title insurance company shall be invested in the same classes of investments, other than title plant and real estate, authorized for the investment of capital, except that one-fourth of such reserve may be invested in preferred or guaranteed stocks or shares of any solvent corporation or business trust, incorporated or existing under the laws of the United States or of any state, district or territory thereof, whose net earnings available for its fixed charges, during either of the two years preceding the date of such investment have been, and during each of the five years preceding such date, have averaged not less than one and one-half times the sum of its average annual fixed charges, as referred to in clause (4) of section 732,¹ if any, and its average annual preferred dividend requirements. For the purposes of this section, such computation shall refer to the fiscal year immediately preceding the date of acquisition of an investment by the insurer, and the term “preferred dividend requirement”, shall include cumulative or noncumulative dividends, whether paid, earned or not.