If a number cannot be tied to a public record, it does not appear.
Where the figures come from
Registered apprenticeship records from federal and state sources come first. Then state agencies, published catalogs, and program pages.
Marketing sites and paid listings are not treated as primary sources.
What a program needs to appear
A name and sponsor, a location, a cost figure (including $0), and a wage or earnings figure.
If both cost and wage are missing, the program is left off.
Dates
Each figure is tied to a source and a date. If we cannot find a number, we leave it blank rather than guess.