There shall be allowed as a credit against the tax imposed on any corporation under this chapter with respect to any taxable year of such corporation commencing on or after January 1, 1997, (1) that has more than two hundred fifty full-time, permanent employees but not more than eight hundred full-time, permanent employees whose wages, salaries or other compensation is paid in this state, as the phrase is used in subsection (b) of section 12-218, an amount equal to five per cent of the amount spent by the corporation on machinery and equipment acquired for and installed in a facility in this state, which amount exceeds the amount spent by such corporation during the preceding income year of the corporation for such expenditures or (2) that has not more than two hundred fifty full-time, permanent employees whose wages, salaries or other compensation is paid in this state, as the phrase is used in subsection (b) of section 12-218, an amount equal to ten per cent of the amount spent by the corporation on machinery and equipment acquired for and installed in a facility in this state, which amount exceeds the amount spent by such corporation during the preceding income year of the corporation for such expenditures. In addition, any amount spent (A) by a corporation whose income year, for federal income tax purposes, commences on the first day of January, February, March, April or May, (B) on machinery and equipment acquired for and installed in a facility in this state, (C) during that portion of its income year in 1995 that expired on May 31, 1995, shall be deemed to have been spent during its income year commencing in 1997 and shall be added to any amount actually spent on machinery and equipment acquired for and installed in a facility in this state during its income year commencing in 1997, provided the credit percentage to which such corporation shall be entitled for its income year commencing in 1997 shall be based on the number of full-time, permanent employees during its income year commencing in 1997.