1. (a) To compute the tax surcharge, the tax computed in Part 18 of this Title, after the deduction of credits allowed pursuant to Part 20 of this Title, is allocated to the MCTD pursuant to section 23-1.3 of this Subpart, and is multiplied by the following applicable rate:

   1. (1) 18 percent for taxable years or portions thereof commencing on or after January 1, 1982 but ending before December 31, 1983;
   2. (2) 17 percent for taxable years or portions thereof ending on or after December 31, 1983 but before December 31, 1986.

Tax Law, § 1455-B(1)