Subject to paragraph (4), in this paragraph:
(I)#
The term “cost proportion” means 75 percent for cost reporting periods beginning in fiscal year 1988, 50 percent for portions of cost reporting periods beginning on or after October 1, 1988 , and ending on or before December 31, 1990 , and 42 percent for portions of cost reporting periods beginning on or after January 1, 1991 .
(II)#
The term “ASC proportion” means 25 percent for cost reporting periods beginning in fiscal year 1988, 50 percent for portions of cost reporting periods beginning on or after October 1, 1988 , and ending on or before December 31, 1990 , and 58 percent for portions of cost reporting periods beginning on or after January 1, 1991 .