issues a written notice to the shareholders of the regulated investment company within 60 days after the close of the company's taxable year indicating the amount of dividends that qualify for the New York subtraction modification referred

(a) Where 100 percent of the income of the regulated investment company is derived from interest on obligations of the United States and its possessions, the written notice should indicate that 100 percent of the income received by the shareholders may be subtracted.

(b) Where less than 100 percent of the income of the regulated investment company is derived from interest on obligations of the United States and its possessions, the written notice should indicate that portion of the shareholder's distribution attributable to such interest that may be subtracted, determined by multiplying the shareholder's distribution by a fraction, the numerator of which is the regulated investment company's interest income on Federal obligations for the taxable year less expenses attributable to such interest income for such year, and the denominator of which is the regulated investment company's taxable income for such year determined in accordance with section 852(b)(2) of the Internal Revenue Code, but without regard to subparagraph (D) of such paragraph (2).