For both sprinkler fitting and plumbing and mechanical adult apprentices, a person already employed by the employer immediately before becoming an adult apprentice must not have their pay reduced because they entered the training agreement; for rate-fixing only, they keep receiving the rate (including all-purpose allowances) of the classification they held immediately before, as it changes from time to time. Otherwise an adult apprentice's pay floor is the greater of two figures: the federal minimum wage with the full industry disability allowance added (sprinkler fitting) or with the full 21.3(a) industry allowance added (plumbing and mechanical); and the general apprentice rate in 18.2.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.