For construction on a covered project for which a public body advertises for bids or proposals for a public works contract on or after January 1, 2027, the applicable percentage is 20%. On or before December 31, 2028, and every other December 31 thereafter, the Secretary shall set the applicable percentage that will apply for the following calendar year. The applicable percentage adopted under this subsection shall be based on, over the previous 2 years: enrollment in State apprenticeship programs; and actual apprenticeship utilization on public works projects. The Secretary may alter the applicable percentage for a covered project to meet any ratio requirements necessary for apprentice or journeyworker supervision in the covered craft.