Use the line of sight method to develop a straight market line. However, this advancement is not important to the company. Never go below minimum wage. The midpoint of each pay grade must be at the center of the pay line.
Internal equity is more important than external equity.
Accordingly, if there is a choice between two pay grades, internal equity will prevail. If a job ends up exactly between two pay grades, put the job in the lower pay grade because the company wants to save money. Use the line of sight method to develop a curvilinear market line. This advancement is important to the company. Never go below minimum wage.