“ For high speed copier paper, offset paper, forms bond, computer printout paper, carbonless paper, file folders, white woven envelopes and for other uncoated printing and writing paper, such as writing and office paper, book paper, cotton fiber paper, and cover stock, the minimum content standard shall be no less than 20 percent postconsumer materials beginning December 31, 1994. This minimum content standard shall be increased to 30 percent beginning on December 31, 1998. ”