(a) The Department of Revenue shall ascertain the total amount of revenue, realized or unrealized, that was lost for all taxable years beginning before January 1, 1987, as a result of the decision of the Supreme Court of Pennsylvania in First Federal Savings and Loan Association of Philadelphia vs. Commonwealth, 515 Pa. 369 (1987). In ascertaining this amount, the department shall consider any refunds, including interest paid, granted to institutions as well as any reductions in settled or resettled taxes or other reductions which arose or are supported by the First Federal decision. The department shall also ascertain the difference in the revenue produced by the tax imposed by this article for taxable years beginning in 1987, 1988, 1989 and 1990 at the rate of twenty per cent and the revenue which would have been received if the tax rate was set at twelve and one-half per cent for such taxable years. After such information has been compiled and determined, the department shall reduce the rate of the tax imposed by this article for taxable years beginning in 1987, 1988, 1989 and 1990 to the nearest one-tenth of a per cent in order that the revenue resulting from the rate of tax in excess of twelve and one-half per cent equals the foregone tax revenues due to the First Federal decision as ascertained pursuant to this section. If such adjustment is made, the department shall reduce and recalculate the tax of each institution for taxable years beginning in 1987, 1988, 1989 and 1990 and shall notify each institution of its reduced tax liability. Each institution shall then be entitled to apply for a cash refund or credit in the manner provided by law, except that no interest shall accrue on the refund or credit granted pursuant to this subsection.

(b) The department shall also submit to the General Assembly the information required to be ascertained by subsection (a) of this section.